Topsheets integrated with heterogenous mass laye

ABSTRACT

An absorbent article and method of making the absorbent article are disclosed. The absorbent article having a topsheet, a backsheet, and an absorbent core structure having one or more layers wherein at least one layer is a heterogeneous mass layer, wherein the topsheet and the heterogeneous mass are integrated such that they reside in the same X-Y plane.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a continuation of, and claims priority under 35U.S.C. § 120 to, U.S. patent application Ser. No. 15/587,894, filed onMay 5, 2017, which claims the benefit, under 35 USC § 119(e), of U.S.Provisional Patent Application Ser. No. 62/332,549, filed on May 6, 2016and U.S. Provisional Patent Application Ser. No. 62/332,472, filed onMay 5, 2016, the entire disclosures of which are fully incorporated byreference herein.

FIELD OF THE INVENTION

The present invention relates to an absorbent structure utilizing aplurality of absorbent core layers that are integrated together in amanner that leads to beneficial physical and performance properties. Theabsorbent core structure is useful in absorbent articles such asdiapers, incontinent briefs, training pants, diaper holders and liners,sanitary hygiene garments, and the like.

BACKGROUND OF THE INVENTION

One of the goals of an absorbent article is to absorb fluid withoutbeing noticeable to the user or others. Ideally, an article would becreated that has the flexibility of a cloth undergarment while beingcapable of absorbing fluid rapidly into the core. However, there isoften a tradeoff between comfort and rate of absorption. Further, thereis often a tradeoff between the permeability of the absorbent articleand the suction provided by the absorbent article. In essence, as a corebecomes more permeable, it traditionally loses some of the ability tocreate suction within the absorbent core.

Further, there is a tradeoff made regarding flexibility and comfortinclusive of fit to body. For example, traditional cellulose based thickproducts focuses on high initial stiffness, recognizing that they willdeform, bunch and degrade while wearing but they nevertheless offer highbulk volume in an effort to attempt to ensure sufficient body coverageis available throughout pad wear. Traditional in market products oftencomposed of airlaid absorbent materials are thinner and morecomfortable, with less initial stiffness, but are designed to betterretain their shape and fit to body during wear by the use of binderssuch as bi-component fibers and latex to attempt to reduce structuralcollapse as the products are worn and loaded by the wearer.

Yet another approach for improved fit to body has been to createspecific humps and valleys, so specific 3 dimensional topographies on aproduct to better macroscopically conform to the intimate geometries.The drawback of such approaches is such topography is ‘macroscopic’ indimensions compared to the scale and complex topography present in theintimate area and at the same time, with the wide range of anatomies andbody sizes, shapes the ability to deliver a preferred product geometryto the body is limited.

Another historical tradeoff that is well known is the need to provide aclose to body fit in order to remove complex liquids such as menstrualfluid closer to the source and yet preserve sufficient panty coverage incase fluid is not captured at the source and the panty is exposed tofluid moving on the body or in body folds that often leads to leakage.

A variety of approaches have been leveraged to balance this competingset of mechanical requirements. On the one end typical approaches haveincluded discrete absorbent elements contained in a tube or highlyfragmented, deformable and stretchable absorbent materials able toconform to a wide variety of complex body shapes. The main limitation ofsuch discrete or decoupled absorbent components is a fundamentalinability to sustain a preferred product to body shape and, or todynamically conform back to a preferred shape following bodilydeformation. The ability to overcome the severe bunching, productbending and buckling of these discrete or decoupled approaches has notbeen demonstrated.

Another series of approaches to solve this complex mechanical-structuralset of requirements has been to design an absorbent system with a seriesof preferred bending locations to force a specific bending mode in theproduct or to leveraging a small number of discrete core pieces or corecutouts to drive specific product shapes. The fundamental challenge thatlimits such approaches (including the one listed above) is three fold,first, breaking the absorbent core into pieces, however small, breaksthe fluid continuity thereby limiting the ability to wick fluid andreduce saturation at the loading point. Second, women's intimate anatomyand body shapes are extremely varied and while creating specific bendingor fold lines and core segments can help create a specific shape, thereis no guarantee that this ‘programmed shape’ can fit such a wide rangeof intimate topography and body shapes. So its effectiveness is limited.A third limitation is that in programing specific bending or foldingmodes the struggle is to sustain these programed shapes during dynamicbody movements in a way that is both comfortable and resilient.

One possible material that has improved comfort are absorbent cores thatutilize absorbent foams. However, because absorbent products that usefoam traditionally have the foam in layers, it cannot be integrated bymechanical means with other layers because the foam will fracture andbreak.

Prior fibrous topsheets require a trade-off between capillarity,permeability, wetting, and rewet or fluid retention properties. If youwant high permeability, you can either make the topsheet philic so thatfluid passes through it fast, but then you are left with a wet topsheetwith either poor rewet values or retention of fluid in the topsheet thatthe wearer (or care giver) can be sensitive to.

Alternatively, you can use a phobic topsheet which may give good rewetvalues but poor wettability or permeability. The poor wettability orpermeability can partially be overcome by using apertures. However, withviscous liquids the apertures may still drain poorly due to the Bondviscosity void gap, i.e., the fluid bridges the aperture rather thandraining through the aperture.

Another alternative to address skin wetness issues is a topsheet with ahigher density, thus yielding higher capillarity pressures to bettercompete for complex and viscous liquids trapped or remaining on thebody. However, unless the secondary topsheet and core layers below thetopsheet have even higher capillarity, the product cannot generateenough capillary suction to properly drain the topsheet. Further,attempts to create a capillarity gradient via densification of thetopsheet through embossing, channels, etc. are also problematic as thedenser topsheet is stiffer to the consumer (comfort issues) and does notdrain efficiently due to the disruption of a capillarity cascade, i.e.each sub layer needs to have higher capillarity that the layer above it.

As such, there exists the need to develop an absorbent structure thatcan, conform to a wide range of intimate topographies and overall bodyshapes and sizes, both statically and dynamically, that is able tofollow her complex body geometry during motion and nevertheless recoverto a preferred geometric shape following motion and be ready to capturefluid closer to the source in a sustained way. Further there remains theneed to be able to deliver this dynamic conforming shape resiliently andcomfortably all without disrupting the critical need to ensure fluidconnectivity so that the primary loading area is adequately drained andsuction at the primary or other loading area(s) is regenerated.

SUMMARY OF THE INVENTION

An absorbent article is disclosed. The absorbent article has a topsheet,a backsheet, and an absorbent core structure comprising one or morelayers. The absorbent structure exhibits an average first cycle PeakForce compression between about 30 gram force and about 1,000 gram forceand an average fifth cycle dry recovery energy between 0.1 mJ and 2.8mJ. A portion of the topsheet is integrated into the absorbent corestructure.

An absorbent article is disclosed. The absorbent article has a topsheet,a backsheet, and an absorbent core structure comprising one or morelayers. The absorbent structure exhibits an average first cycle PeakForce compression between about 30 gram force and about 1,000 gram forceand an average fifth cycle dry recovery energy between 0.1 mJ and 2.8mJ. The absorbent article comprises wells.

BRIEF DESCRIPTION OF THE DRAWINGS

While the specification concludes with claims particularly pointing outand distinctly claiming the subject matter of the present invention, itis believed that the invention can be more readily understood from thefollowing description taken in connection with the accompanyingdrawings, in which:

FIG. 1 is a perspective view of an apparatus for forming the web for usein the present invention.

FIG. 2 is a cross-sectional depiction of a portion of the apparatusshown in FIG. 1.

FIG. 3 is a perspective view of a web suitable for use in an article.

FIG. 4 is an enlarged view of a portion of the web shown in FIG. 3.

FIG. 5 is a perspective view of a portion of the apparatus for formingone embodiment of a web suitable for use in an article.

FIG. 6 is an enlarged perspective view of a portion of the apparatus forforming a web suitable for use in an article.

FIG. 7 is an enlarged view of a portion of another embodiment of a websuitable for use in an article.

FIG. 8 is a schematic representation of an apparatus for making a web.

FIG. 9 is a perspective view of one example of an apparatus for formingthe nonwoven material described herein.

FIG. 10 is an enlarged perspective view of a portion of the male rollshown in FIG. 9.

FIG. 10A is an enlarged schematic side view showing an example of asurface texture formed by knurling a forming member.

FIG. 10A is a schematic side view of a male element with tapered sidewalls.

FIG. 10B is a schematic side view of a male element with undercut sidewalls.

FIG. 10C is an enlarged perspective view of a portion of a male rollhaving an alternative configuration.

FIG. 10D is a schematic side view of a male element with a rounded top.

FIG. 10E is a magnified photograph of the top surface of a male elementthat has been roughened by sandblasting.

FIG. 10F is a magnified photograph of the top surface of a male elementthat has a relatively smooth surface formed by machining the same.

FIG. 10G is a schematic side view showing an example of macro textureand micro texture that can be created by knurling the surface of a maleor female forming member.

FIG. 11 is an enlarged perspective view showing the nip between therolls shown in FIG. 9.

FIG. 11A is a schematic side view of a recess in a female forming memberwith a rounded top edge or rim.

FIG. 11B is a photograph of a second forming member having a surfacethat has been roughened with diamond type knurling.

FIG. 12 is a perspective view of one embodiment of a sanitary napkin.

FIG. 13 is a cross-sectional view of the sanitary napkin of FIG. 1,taken through line 2-2.

FIG. 14 is an enlarged section of FIG. 13.

FIG. 15 is an SEM micrograph of a heterogeneous mass.

FIG. 16 is an SEM micrograph of a heterogeneous mass.

FIG. 17 shows a top view of a topsheet.

FIG. 18 shows a second top view of the topsheet of FIG. 17.

FIG. 19 shows a cross section of FIG. 18.

FIG. 20 shows a top view of a topsheet.

FIG. 21 shows a second top view of the topsheet of FIG. 20.

FIG. 22 shows a cross section of FIG. 21.

FIG. 23 zoomed in portion of the cross section of FIG. 22.

FIG. 24 shows a top view of a topsheet.

FIG. 25 shows a cross section of FIG. 24.

FIG. 26 zoomed in portion of the cross section of FIG. 25.

FIG. 27 is a top view of an alternative pattern.

FIG. 28 shows a top view of alternative patterns.

FIG. 29 shows a top view of alternative patterns.

FIG. 30 shows the apparatus for a test method.

FIG. 31A-B relate to the test method of FIG. 30.

FIG. 32A-B relate to the test method of FIG. 30.

FIG. 33 shows an apparatus for a test method.

FIG. 34 shows an apparatus for a test method.

FIG. 35 shows an apparatus for a test method.

FIG. 36a shows a plot of an NMR profile.

FIG. 36b shows a plot of an NMR profile.

FIG. 37 shows a kinetic plot of an NMR profile.

DETAILED DESCRIPTION OF THE INVENTION

As used herein, the term “absorbent core structure” refers to anabsorbent core that is has two or more absorbent core layers. Eachabsorbent core layer is capable acquiring and transporting or retainingfluid.

As used herein, the term “bicomponent fibers” refers to fibers whichhave been formed from at least two different polymers extruded fromseparate extruders but spun together to form one fiber. Bicomponentfibers are also sometimes referred to as conjugate fibers ormulticomponent fibers. The polymers are arranged in substantiallyconstantly positioned distinct zones across the cross-section of thebicomponent fibers and extend continuously along the length of thebicomponent fibers. The configuration of such a bicomponent fiber maybe, for example, a sheath/core arrangement wherein one polymer issurrounded by another, or may be a side-by-side arrangement, a piearrangement, or an “islands-in-the-sea” arrangement.

As used herein, the term “biconstituent fibers” refers to fibers whichhave been formed from at least two polymers extruded from the sameextruder as a blend. Biconstituent fibers do not have the variouspolymer components arranged in relatively constantly positioned distinctzones across the cross-sectional area of the fiber and the variouspolymers are usually not continuous along the entire length of thefiber, instead usually forming fibrils which start and end at random.Biconstituent fibers are sometimes also referred to as multiconstituentfibers.

As used herein, “complex liquids” are defined as fluids that arenon-Newtonian, whose rheological properties are complex that change withshear and commonly shear thin. Such liquids commonly contain more thanone phase (red blood cells plus vaginal mucous) that may phase separateon contact with topsheets and absorbent materials. In addition, complexliquids such as menstrual fluid may contain long chain proteinsexhibiting stringy properties, high cohesive force within a dropletallowing for droplet elongation without breaking. Complex liquids mayhave solids (menstrual and runny feces).

The term “disposable” is used herein to describe articles, which are notintended to be laundered or otherwise restored or reused as an article(i.e. they are intended to be discarded after a single use and possiblyto be recycled, composted or otherwise disposed of in an environmentallycompatible manner). The absorbent article comprising an absorbentstructure according to the present invention can be for example asanitary napkin or a panty liner or an adult incontinence article or ababy diaper or a wound dressing. The absorbent structure of the presentinvention will be herein described in the context of a typical absorbentarticle, such as, for example, a sanitary napkin. Typically, sucharticles can comprise a liquid pervious topsheet, a backsheet and anabsorbent core intermediate the topsheet and the backsheet.

As used herein, an “enrobeable element” refers to an element that may beenrobed by the foam. The enrobeable element may be, for example, afiber, a group of fibers, a tuft, or a section of a film between twoapertures. It is understood that other elements are contemplated by thepresent invention.

A “fiber” as used herein, refers to any material that can be part of afibrous structure. Fibers can be natural or synthetic. Fibers can beabsorbent or non-absorbent.

A “fibrous structure” as used herein, refers to materials which can bebroken into one or more fibers. A fibrous structure can be absorbent oradsorbent. A fibrous structure can exhibit capillary action as well asporosity and permeability.

As used herein, the term “meltblowing” refers to a process in whichfibers are formed by extruding a molten thermoplastic material through aplurality of fine, usually circular, die capillaries as molten threadsor filaments into converging high velocity, usually heated, gas (forexample air) streams which attenuate the filaments of moltenthermoplastic material to reduce their diameter. Thereafter, themeltblown fibers are carried by the high velocity gas stream and aredeposited on a collecting surface, often while still tacky, to form aweb of randomly dispersed meltblown fibers.

As used herein, the term “monocomponent” fiber refers to a fiber formedfrom one or more extruders using only one polymer. This is not meant toexclude fibers formed from one polymer to which small amounts ofadditives have been added for coloration, antistatic properties,lubrication, hydrophilicity, etc. These additives, for example titaniumdioxide for coloration, are generally present in an amount less thanabout 5 weight percent and more typically about 2 weight percent.

As used herein, the term “non-round fibers” describes fibers having anon-round cross-section, and includes “shaped fibers” and “capillarychannel fibers.” Such fibers can be solid or hollow, and they can betri-lobal, delta-shaped, and are preferably fibers having capillarychannels on their outer surfaces. The capillary channels can be ofvarious cross-sectional shapes such as “U-shaped”, “H-shaped”,“C-shaped” and “V-shaped”. One practical capillary channel fiber isT-401, designated as 4DG fiber available from Fiber InnovationTechnologies, Johnson City, Tenn. T-401 fiber is a polyethyleneterephthalate (PET polyester).

As used herein, the term “nonwoven web” refers to a web having astructure of individual fibers or threads which are interlaid, but notin a repeating pattern as in a woven or knitted fabric, which do nottypically have randomly oriented fibers. Nonwoven webs or fabrics havebeen formed from many processes, such as, for example, meltblowingprocesses, spunbonding processes, spunlacing processes, hydroentangling,airlaying, and bonded carded web processes, including carded thermalbonding. The basis weight of nonwoven fabrics is usually expressed ingrams per square meter (gsm). The basis weight of the laminate web isthe combined basis weight of the constituent layers and any other addedcomponents. Fiber diameters are usually expressed in microns; fiber sizecan also be expressed in denier, which is a unit of weight per length offiber. The basis weight of laminate webs suitable for use in an articleof the present invention can range from 10 gsm to 100 gsm, depending onthe ultimate use of the web.

As used herein, the term “polymer” generally includes, but is notlimited to, homopolymers, copolymers, such as for example, block, graft,random and alternating copolymers, terpolymers, etc., and blends andmodifications thereof. In addition, unless otherwise specificallylimited, the term “polymer” includes all possible geometricconfigurations of the material. The configurations include, but are notlimited to, isotactic, atactic, syndiotactic, and random symmetries.

As used herein, “spunbond fibers” refers to small diameter fibers whichare formed by extruding molten thermoplastic material as filaments froma plurality of fine, usually circular capillaries of a spinneret withthe diameter of the extruded filaments then being rapidly reduced.Spunbond fibers are generally not tacky when they are deposited on acollecting surface. Spunbond fibers are generally continuous and haveaverage diameters (from a sample size of at least 10 fibers) larger than7 microns, and more particularly, between about 10 and 40 microns.

As used herein, a “strata” or “stratum” relates to one or more layerswherein the components within the stratum are intimately combinedwithout the necessity of an adhesive, pressure bonds, heat welds, acombination of pressure and heat bonding, hydro-entangling,needlepunching, ultrasonic bonding, or similar methods of bonding knownin the art such that individual components may not be wholly separatedfrom the stratum without affecting the physical structure of the othercomponents. The skilled artisan should understand that while separatebonding is unnecessary between the strata, bonding techniques could beemployed to provide additional integrity depending on the intended use.

As used herein, a “tuft” or chad relates to discrete integral extensionsof the fibers of a nonwoven web. Each tuft can comprise a plurality oflooped, aligned fibers extending outwardly from the surface of the web.In another embodiment each tuft can comprise a plurality of non-loopedfibers that extend outwardly from the surface of the web. In anotherembodiment, each tuft can comprise a plurality of fibers which areintegral extensions of the fibers of two or more integrated nonwovenwebs.

As used herein, a “well” or “wells” relates to one or more funnel shapedvolumetric spaces wherein a portion of a fibrous layer has beenintegrated into a second fibrous layer without creating a higher densityzone. The wells may be circular or elongated circular patterns wherethere is a smooth transition from a horizontal plane to a vertical planealong the surface of the well. Wells are further defined in that one ormore fibers from the first fibrous layer and one or more fibers from thesecond fibrous layer create the outer surface of the well within thesame x-y plane. The second fibrous layer is either a fluid transfer or afluid storage layer. A well may exhibit variations in the density of theside wall or the distal end, however the density of the distal end isnot greater than the average density of the original first fibrouslayer. Additionally, a well may be defined as a point of discontinuityin the topsheet wherein one or more fibers of the topsheet or one ormore portions of the topsheet have been changed in orientation from anX-Y plane to a Z direction plane entering an X-Y plane of the absorbentcore structure.

While particular embodiments of the present invention have beenillustrated and described, it would be obvious to those skilled in theart that various other changes and modifications can be made withoutdeparting from the spirit and scope of the invention.

GENERAL SUMMARY

An absorbent article structure is disclosed. The absorbent article hasone of a topsheet, a secondary topsheet, or both combined with a fibrousweb having a high capacity absorbent.

The fibrous web may be a heterogeneous mass comprising a fibrous web andone or more pieces of open cell foam intermixed within the fibrous weband/or enrobing one or more fibers within the fibrous web.

The fibrous web may be the upper layer of an absorbent core. Theabsorbent core may be a two layer system wherein the upper layer isheterogeneous mass layer comprising one or more enrobeable elements andone or more discrete open-cell foam pieces. The upper layerheterogeneous mass layer may be a stratum as defined above. The lowerlayer may be an absorbent layer that comprises superabsorbent polymer.The absorbent core structure may comprise additional layers below theabsorbent layer that comprises superabsorbent polymer. The upper layerheterogeneous mass layer may be integrated with a topsheet usingformation means.

The absorbent core structure may comprise a heterogeneous mass layer ormay utilize methods or parameters such as those described in US PatentPublication No. 2015-0335498, filed May 19, 2015; US Patent PublicationNo. 2015-0374560, Jun. 25, 2015; US Patent Publication No. 2015-0374561filed Jun. 26, 2015; US Patent Publication No. 2016-0346805 filed Mar.23, 2016; US Patent Publication No. 2015-0374561 filed Jun. 25, 2015; USPatent Publication No. 2016-0287452 filed Mar. 30, 2016; US PatentPublication No. 2017-0071795 filed Nov. 4, 2016; U.S. patent applicationSer. No. 15/344,273 filed Nov. 4, 2016; U.S. patent application Ser. No.15/344,294 filed Nov. 4, 2016; US Patent Publication No. 2015-0313770filed May 5, 2015; US Patent Publication No. 2016-0375458 filed Jun. 28,2016; U.S. patent application Ser. No. 15/344,050 filed Nov. 4, 2016;U.S. patent application Ser. No. 15/344,117 filed Nov. 4, 2016; U.S.patent application Ser. No. 15/344,177 filed Nov. 4, 2016; U.S. patentapplication Ser. No. 15/344,198 filed Nov. 4, 2016; U.S. patentapplication Ser. No. 15/344,221 filed Nov. 4, 2016; U.S. patentapplication Ser. No. 15/344,239 filed Nov. 4, 2016; U.S. patentapplication Ser. No. 15/344,255 filed Nov. 4, 2016; U.S. patentapplication Ser. No. 15/464,733 filed Nov. 4, 2016; U.S. ProvisionalPatent Application No. 62/332,549 filed May 6, 2016; U.S. ProvisionalPatent Application No. 62/332,472 filed May 5, 2016; U.S. ProvisionalPatent Application No. 62/437,208 filed Dec. 21, 2016; U.S. ProvisionalPatent Application No. 62/437,225 filed Dec. 21, 2016; U.S. ProvisionalPatent Application No. 62/437,241 filed Dec. 21, 2016; U.S. ProvisionalPatent Application No. 62/437,259 filed Dec. 21, 2016, or U.S.Provisional Patent Application No. 62/500,920 filed May 3, 2017. Theheterogeneous mass layer has a depth, a width, and a height.

The absorbent core structure may comprise a substrate and superabsorbentpolymer layer as those described in U.S. Pat. No. 8,124,827 filed onDec. 2, 2008 (Tamburro); U.S. application Ser. No. 12/718,244 publishedon Sep. 9, 2010; U.S. application Ser. No. 12/754,935 published on Oct.14, 2010; or U.S. Pat. No. 8,674,169 issued on Mar. 18, 2014.

The one or more discrete portions of foam pieces enrobe the enrobeableelements. The discrete portions of foam pieces are open-celled foam. Inan embodiment, the foam is a High Internal Phase Emulsion (HIPE) foam.In an embodiment, one continuous piece of open cell foam may enrobemultiple enrobeable elements, such as, for example, the fibers that makeup the upper layer of a nonwoven web.

In the following description of the invention, the surface of thearticle, or of each component thereof, which in use faces in thedirection of the wearer is called wearer-facing surface. Conversely, thesurface facing in use in the direction of the garment is calledgarment-facing surface. The absorbent article of the present invention,as well as any element thereof, such as, for example the absorbent core,has therefore a wearer-facing surface and a garment-facing surface.

The heterogeneous mass layer contains one or more discrete open-cellfoam pieces foams that are integrated into the heterogeneous masscomprising one or more enrobeable elements integrated into the one ormore open-cell foams such that the two may be intertwined.

The open-cell foam pieces may comprise between 1% of the heterogeneousmass by volume to 99% of the heterogeneous mass by volume, such as, forexample, 5% by volume, 10% by volume, 15% by volume, 20% by volume, 25%by volume, 30% by volume, 35% by volume, 40% by volume, 45% by volume,50% by volume, 55% by volume, 60% by volume, 65% by volume, 70% byvolume, 75% by volume, 80% by volume, 85% by volume, 90% by volume, or95% by volume.

The heterogeneous mass layer may have void space found between theenrobeable elements (e.g. fibers), between the enrobeable elements andthe enrobed enrobeable elements (e.g. fibers enrobed by open cell foam),and between enrobed enrobeable elements. The void space may contain gas.The void space may represent between 1% and 95% of the total volume fora fixed amount of volume of the heterogeneous mass, such as, forexample, 5%, 10%, 15%, 20%, 25%, 30%, 35%, 40%, 45%, 50%, 55%, 60%, 65%,70%, 75%, 80%, 85%, 90% of the total volume for a fixed amount of volumeof the heterogeneous mass.

The combination of open-cell foam pieces and void space within theheterogeneous mass may exhibit an absorbency of between 10 g/g to 200g/g of the heterogeneous mass, such as for example, 40 g/g, 60 g/g, 80g/g, 100 g/g, 120 g/g, 140 g/g 160 g/g 180 g/g or 190 g/g of theheterogeneous mass. Absorbency may be quantified according to the EDANANonwoven

Absorption method 10.4-02.

The open-cell foam pieces are discrete foam pieces intertwined withinand throughout a heterogeneous mass such that the open-cell foam enrobesone or more of the enrobeable elements such as, for example, fiberswithin the mass. The open-cell foam may be polymerized around theenrobeable elements.

In an embodiment, a discrete open-cell foam piece may enrobe more thanone enrobeable element. The enrobeable elements may be enrobed togetheras a bunch. Alternatively, more than one enrobeable element may beenrobed by the discrete open-cell foam piece without contacting anotherenrobeable element.

In an embodiment, the open-cell foam pieces may enrobe an enrobeableelement such that the enrobeable element is enrobed along the enrobeableelements axis for between 5% and 95% of the length along the enrobeableelement's axis. For example, a single fiber may be enrobed along thelength of the fiber for a distance greater than 50% of the entire lengthof the fiber. In an embodiment, an enrobeable element may have between5% and 100% of its surface area enrobed by one or more open-cell foampieces.

In an embodiment, two or more open-cell foam pieces may enrobe the sameenrobeable element such that the enrobeable element is enrobed along theenrobeable elements axis for between 5% and 100% of the length along theenrobeable element's axis.

The open-cell foam pieces enrobe the enrobeable elements such that alayer surrounds the enrobeable element at a given cross section. Thelayer surrounding the enrobeable element at a given cross section may bebetween 0.01 mm to 100 mm such as, for example, 0.1 mm, 0.2 mm, 0.3 mm,0.4 mm, 0.5 mm, 0.6 mm, 0.7 mm, 0.8 mm, 0.9 mm, 1.0 mm, 1.2 mm, 1.4 mm,1.6 mm, 1.8 mm, 2.0 mm, 2.2 mm, 2.4 mm, 2.6 mm, 2.8 mm, or 3 mm. Thelayer may not be equivalent in dimension at all points along the crosssection of the enrobeable element. For example, in an embodiment, anenrobeable element may be enrobed by 0.5 mm at one point along the crosssection and by 1.0 mm at a different point along the same cross section.

The open-cell foam pieces are considered discrete in that they are notcontinuous throughout the entire heterogeneous mass layer. Notcontinuous throughout the entire heterogeneous mass layer representsthat at any given point in the heterogeneous mass layer, the open-cellabsorbent foam is not continuous in at least one of the cross sectionsof a longitudinal, a vertical, and a lateral plane of the heterogeneousmass layer. In a non-limiting embodiment, the absorbent foam is notcontinuous in the lateral and the vertical planes of the cross sectionfor a given point in the heterogeneous mass layer. In a non-limitingembodiment, the absorbent foam is not continuous in the longitudinal andthe vertical planes of the cross section for a given point in theheterogeneous mass layer. In a non-limiting embodiment, the absorbentfoam is not continuous in the longitudinal and the lateral planes of thecross section for a given point in the heterogeneous mass layer.

In an embodiment wherein the open-cell foam is not continuous in atleast one of the cross sections of the longitudinal, the vertical, andthe lateral plane of the heterogeneous mass, one or both of either theenrobeable elements or the open-cell foam pieces may be bi-continuousthroughout the heterogeneous mass.

The open-cell foam pieces may be located at any point in theheterogeneous mass. In a non-limiting embodiment, a foam piece may besurrounded by the elements that make up the enrobeable elements. In anon-limiting embodiment a foam piece may be located on the outerperimeter of the heterogeneous mass such that only a portion of the foampiece is entangled with the elements of the heterogeneous mass.

In a non-limiting embodiment, the open-cell foam pieces may expand uponbeing contacted by a fluid to form a channel of discrete open-cell foampieces. The open-cell foam pieces may or may not be in contact prior tobeing expanded by a fluid.

An open-celled foam may be integrated onto the enrobeable elements priorto being polymerized. In a non-limiting embodiment the open-cell foampieces may be partially polymerized prior to being impregnated into oronto the enrobeable elements such that they become intertwined. Afterbeing impregnated into or onto the enrobeable elements, the open-celledfoam in either a liquid or solid state are polymerized to form one ormore open-cell foam pieces.

The open cell foam pieces may be impregnated prior to polymerizationinto or onto two or more different enrobeable elements that are combinedto create a heterogeneous mixture of enrobeable elements. The two ormore different enrobeable elements may be intertwined such that oneenrobeable element may be surrounded by multiples of the secondenrobeable element, such as, for example by using more than one type offiber in a mixture of fibers or by coating one or more fibers withsurfactant. The two or more different enrobeable elements may be layeredwithin the heterogeneous mass along any of the vertical, longitudinal,and/or lateral planes such that the enrobeable elements are profiledwithin the heterogeneous mass for an enrobeable element inherentproperty or physical property, such as, for example, hydrophobicity,fiber diameter, fiber or composition. It is understood that any inherentproperty or physical property of the enrobeable elements listed iscontemplated herein.

The open-celled foam may be polymerized using any known methodincluding, for example, heat, UV, and infrared. Following thepolymerization of a water in oil open-cell foam emulsion, the resultingopen-cell foam is saturated with aqueous phase that needs to be removedto obtain a substantially dry open-cell foam. Removal of the saturatedaqueous phase or dewatering may occur using nip rollers, and vacuum.Utilizing a nip roller may also reduce the thickness of theheterogeneous mass such that the heterogeneous mass will remain thinuntil the open-cell foam pieces entwined in the heterogeneous mass areexposed to fluid.

Dependent upon the desired foam density, polymer composition, specificsurface area, or pore size (also referred to as cell size), theopen-celled foam may be made with different chemical composition,physical properties, or both. For instance, dependent upon the chemicalcomposition, an open-celled foam may have a density of 0.0010 g/cc toabout 0.25 g/cc. Preferred 0.04 g/cc.

Open-cell foam pore sizes may range in average diameter of from 1 to 800μm, such as, for example, between 50 and 700 μm, between 100 and 600 μm,between 200 and 500 μm, between 300 and 400 μm.

In some embodiments, the foam pieces have a relatively uniform cellsize. For example, the average cell size on one major surface may beabout the same or vary by no greater than 10% as compared to theopposing major surface. In other embodiments, the average cell size ofone major surface of the foam may differ from the opposing surface. Forexample, in the foaming of a thermosetting material it is not uncommonfor a portion of the cells at the bottom of the cell structure tocollapse resulting in a lower average cell size on one surface.

The foams produced from the present invention are relativelyopen-celled. This refers to the individual cells or pores of the foambeing in substantially unobstructed communication with adjoining cells.The cells in such substantially open-celled foam structures haveintercellular openings or windows that are large enough to permit readyfluid transfer from one cell to another within the foam structure. Forpurpose of the present invention, a foam is considered “open-celled” ifat least about 80% of the cells in the foam that are at least 1 μm inaverage diameter size are in fluid communication with at least oneadjoining cell.

In addition to being open-celled, in certain embodiments foams aresufficiently hydrophilic to permit the foam to absorb aqueous fluids,for example the internal surfaces of a foam may be rendered hydrophilicby residual hydrophilizing surfactants or salts left in the foamfollowing polymerization, by selected post-polymerization foam treatmentprocedures (as described hereafter), or combinations of both.

In certain embodiments, for example when used in certain absorbentarticles, an open-cell foam may be flexible and exhibit an appropriateglass transition temperature (Tg). The Tg represents the midpoint of thetransition between the glassy and rubbery states of the polymer.

In certain embodiments, the Tg of this region will be less than about200° C. for foams used at about ambient temperature conditions, incertain other embodiments less than about 90° C. The Tg may be less than50° C.

The open-cell foam pieces may be distributed in any suitable mannerthroughout the heterogeneous mass. In an embodiment, the open-cell foampieces may be profiled along the vertical axis such that smaller piecesare located above larger pieces. Alternatively, the pieces may beprofiled such that smaller pieces are below larger pieces. In anotherembodiment, the open-cell pieces may be profiled along a vertical axissuch that they alternate in size along the axis.

In an embodiment the open-cell foam pieces may be profiled along any oneof the longitudinal, lateral, or vertical axis based on one or morecharacteristics of the open-cell foam pieces. Characteristics by whichthe open-cell foam pieces may be profiled within the heterogeneous massmay include, for example, absorbency, density, cell size, andcombinations thereof.

In an embodiment, the open-cell foam pieces may be profiled along anyone of the longitudinal, lateral, or vertical axis based on thecomposition of the open-cell foam. The open-cell foam pieces may haveone composition exhibiting desirable characteristics in the front of theheterogeneous mass and a different composition in the back of theheterogeneous mass designed to exhibit different characteristics. Theprofiling of the open-cell foam pieces may be either symmetric orasymmetric about any of the prior mentioned axes or orientations.

The open-cell foam pieces may be distributed along the longitudinal andlateral axis of the heterogeneous mass in any suitable form. In anembodiment, the open-cell foam pieces may be distributed in a mannerthat forms a design or shape when viewed from a top planar view. Theopen-cell foam pieces may be distributed in a manner that forms stripes,ellipticals, squares, or any other known shape or pattern.

In an embodiment, different types of foams may be used in oneheterogeneous mass. For example, some of the foam pieces may bepolymerized HIPE while other pieces may be made from polyurethane. Thepieces may be located at specific locations within the mass based ontheir properties to optimize the performance of the heterogeneous mass.

In an embodiment, the open-celled foam is a thermoset polymeric foammade from the polymerization of a High Internal Phase Emulsion (HIPE),also referred to as a polyHIPE. To form a HIPE, an aqueous phase and anoil phase are combined in a ratio between about 8:1 and 140:1. Incertain embodiments, the aqueous phase to oil phase ratio is betweenabout 10:1 and about 75:1, and in certain other embodiments the aqueousphase to oil phase ratio is between about 13:1 and about 65:1. This istermed the “water-to-oil” or W:0 ratio and can be used to determine thedensity of the resulting polyHIPE foam. As discussed, the oil phase maycontain one or more of monomers, co-monomers, photo-initiators,cross-linkers, and emulsifiers, as well as optional components. Thewater phase will contain water and in certain embodiments one or morecomponents such as electrolyte, initiator, or optional components.

The open-cell foam can be formed from the combined aqueous and oilphases by subjecting these combined phases to shear agitation in amixing chamber or mixing zone. The combined aqueous and oil phases aresubjected to shear agitation to produce a stable HIPE having aqueousdroplets of the desired size. An initiator may be present in the aqueousphase, or an initiator may be introduced during the foam making process,and in certain embodiments, after the HIPE has been formed. The emulsionmaking process produces a HIPE where the aqueous phase droplets aredispersed to such an extent that the resulting HIPE foam will have thedesired structural characteristics. Emulsification of the aqueous andoil phase combination in the mixing zone may involve the use of a mixingor agitation device such as an impeller, by passing the combined aqueousand oil phases through a series of static mixers at a rate necessary toimpart the requisite shear, or combinations of both. Once formed, theHIPE can then be withdrawn or pumped from the mixing zone. One methodfor forming HIPEs using a continuous process is described in U.S. Pat.No. 5,149,720 (DesMarais et al), issued Sep. 22, 1992; U.S. Pat. No.5,827,909 (DesMarais) issued Oct. 27, 1998; and U.S. Pat. No. 6,369,121(Catalfamo et al.) issued Apr. 9, 2002.

The emulsion can be withdrawn or pumped from the mixing zone andimpregnated into or onto a mass prior to being fully polymerized. Oncefully polymerized, the foam pieces and the elements are intertwined suchthat discrete foam pieces are bisected by the elements comprising themass and such that parts of discrete foam pieces enrobe portions of oneor more of the elements comprising the heterogeneous mass.

Following polymerization, the resulting foam pieces are saturated withaqueous phase that needs to be removed to obtain substantially dry foampieces. In certain embodiments, foam pieces can be squeezed free of mostof the aqueous phase by using compression, for example by running theheterogeneous mass comprising the foam pieces through one or more pairsof nip rollers. The nip rollers can be positioned such that they squeezethe aqueous phase out of the foam pieces. The nip rollers can be porousand have a vacuum applied from the inside such that they assist indrawing aqueous phase out of the foam pieces. In certain embodiments,nip rollers can be positioned in pairs, such that a first nip roller islocated above a liquid permeable belt, such as a belt having pores orcomposed of a mesh-like material and a second opposing nip roller facingthe first nip roller and located below the liquid permeable belt. One ofthe pair, for example the first nip roller can be pressurized while theother, for example the second nip roller, can be evacuated, so as toboth blow and draw the aqueous phase out the of the foam. The niprollers may also be heated to assist in removing the aqueous phase. Incertain embodiments, nip rollers are only applied to non-rigid foams,that is, foams whose walls would not be destroyed by compressing thefoam pieces.

In certain embodiments, in place of or in combination with nip rollers,the aqueous phase may be removed by sending the foam pieces through adrying zone where it is heated, exposed to a vacuum, or a combination ofheat and vacuum exposure. Heat can be applied, for example, by runningthe foam though a forced air oven, IR oven, microwave oven or radiowaveoven. The extent to which a foam is dried depends on the application. Incertain embodiments, greater than 50% of the aqueous phase is removed.In certain other embodiments greater than 90%, and in still otherembodiments greater than 95% of the aqueous phase is removed during thedrying process.

In an embodiment, open-cell foam is produced from the polymerization ofthe monomers having a continuous oil phase of a High Internal PhaseEmulsion (RIPE). The HIPE may have two phases. One phase is a continuousoil phase having monomers that are polymerized to form a HIPE foam andan emulsifier to help stabilize the HIPE. The oil phase may also includeone or more photo-initiators. The monomer component may be present in anamount of from about 80% to about 99%, and in certain embodiments fromabout 85% to about 95% by weight of the oil phase. The emulsifiercomponent, which is soluble in the oil phase and suitable for forming astable water-in-oil emulsion may be present in the oil phase in anamount of from about 1% to about 20% by weight of the oil phase. Theemulsion may be formed at an emulsification temperature of from about10° C. to about 130° C. and in certain embodiments from about 50° C. toabout 100° C.

In general, the monomers will include from about 20% to about 97% byweight of the oil phase at least one substantially water-insolublemonofunctional alkyl acrylate or alkyl methacrylate. For example,monomers of this type may include C₄-C₁₈ alkyl acrylates and C₂-C₁₈methacrylates, such as ethylhexyl acrylate, butyl acrylate, hexylacrylate, octyl acrylate, nonyl acrylate, decyl acrylate, isodecylacrylate, tetradecyl acrylate, benzyl acrylate, nonyl phenyl acrylate,hexyl methacrylate, 2-ethylhexyl methacrylate, octyl methacrylate, nonylmethacrylate, decyl methacrylate, isodecyl methacrylate, dodecylmethacrylate, tetradecyl methacrylate, and octadecyl methacrylate.

The oil phase may also have from about 2% to about 40%, and in certainembodiments from about 10% to about 30%, by weight of the oil phase, asubstantially water-insoluble, polyfunctional crosslinking alkylacrylate or methacrylate. This crosslinking co-monomer, or cross-linker,is added to confer strength and resilience to the resulting HIPE foam.Examples of crosslinking monomers of this type may have monomerscontaining two or more activated acrylate, methacrylate groups, orcombinations thereof. Nonlimiting examples of this group include1,6-hexanedioldiacrylate, 1,4-butanedioldimethacrylate,trimethylolpropane triacrylate, trimethylolpropane trimethacrylate,1,12-dodecyldimethacrylate, 1,14-tetradecanedioldimethacrylate, ethyleneglycol dimethacrylate, neopentyl glycoldiacrylate(2,2-dimethylpropanediol diacrylate), hexanediol acrylatemethacrylate, glucose pentaacrylate, sorbitan pentaacrylate, and thelike. Other examples of cross-linkers contain a mixture of acrylate andmethacrylate moieties, such as ethylene glycol acrylate-methacrylate andneopentyl glycol acrylate-methacrylate. The ratio ofmethacrylate:acrylate group in the mixed cross-linker may be varied from50:50 to any other ratio as needed.

Any third substantially water-insoluble co-monomer may be added to theoil phase in weight percentages of from about 0% to about 15% by weightof the oil phase, in certain embodiments from about 2% to about 8%, tomodify properties of the HIPE foams. In certain embodiments,“toughening” monomers may be desired which impart toughness to theresulting HIPE foam. These include monomers such as styrene, vinylchloride, vinylidene chloride, isoprene, and chloroprene. Without beingbound by theory, it is believed that such monomers aid in stabilizingthe HIPE during polymerization (also known as “curing”) to provide amore homogeneous and better formed HIPE foam which results in bettertoughness, tensile strength, abrasion resistance, and the like. Monomersmay also be added to confer flame retardancy as disclosed in U.S. Pat.No. 6,160,028 (Dyer) issued Dec. 12, 2000. Monomers may be added toconfer color, for example vinyl ferrocene, fluorescent properties,radiation resistance, opacity to radiation, for example leadtetraacrylate, to disperse charge, to reflect incident infrared light,to absorb radio waves, to form a wettable surface on the HIPE foamstruts, or for any other desired property in a HIPE foam. In some cases,these additional monomers may slow the overall process of conversion ofHIPE to HIPE foam, the tradeoff being necessary if the desired propertyis to be conferred. Thus, such monomers can be used to slow down thepolymerization rate of a HIPE. Examples of monomers of this type canhave styrene and vinyl chloride.

The oil phase may further contain an emulsifier used for stabilizing theHIPE. Emulsifiers used in a HIPE can include: (a) sorbitan monoesters ofbranched C₁₆-C₂₄ fatty acids; linear unsaturated C₁₆-C₂₂ fatty acids;and linear saturated C₁₂-C₁₄ fatty acids, such as sorbitan monooleate,sorbitan monomyristate, and sorbitan monoesters, sorbitan monolauratediglycerol monooleate (DGMO), polyglycerol monoisostearate (PGMIS), andpolyglycerol monomyristate (PGMM); (b) polyglycerol monoesters of-branched C₁₆-C₂₄ fatty acids, linear unsaturated C₁₆-C₂₂ fatty acids,or linear saturated C₁₂-C₁₄ fatty acids, such as diglycerol monooleate(for example diglycerol monoesters of C18:1 fatty acids), diglycerolmonomyristate, diglycerol monoisostearate, and diglycerol monoesters;(c) diglycerol monoaliphatic ethers of -branched C₁₆-C₂₄ alcohols,linear unsaturated C₁₆-C₂₂ alcohols, and linear saturated C₁₂-C₁₄alcohols, and mixtures of these emulsifiers. See U.S. Pat. No. 5,287,207(Dyer et al.), issued Feb. 7, 1995 and U.S. Pat. No. 5,500,451 (Goldmanet al.) issued Mar. 19, 1996. Another emulsifier that may be used ispolyglycerol succinate (PGS), which is formed from an alkyl succinate,glycerol, and triglycerol.

Such emulsifiers, and combinations thereof, may be added to the oilphase so that they can have between about 1% and about 20%, in certainembodiments from about 2% to about 15%, and in certain other embodimentsfrom about 3% to about 12% by weight of the oil phase. In certainembodiments, co-emulsifiers may also be used to provide additionalcontrol of cell size, cell size distribution, and emulsion stability,particularly at higher temperatures, for example greater than about 65°C. Examples of co-emulsifiers include phosphatidyl cholines andphosphatidyl choline-containing compositions, aliphatic betaines, longchain C₁₂-C₂₂ dialiphatic quaternary ammonium salts, short chain C₁-C₄dialiphatic quaternary ammonium salts, long chain C₁₂-C₂₂dialkoyl(alkenoyl)-2-hydroxyethyl, short chain C₁-C₄ dialiphaticquaternary ammonium salts, long chain C₁₂-C₂₂ dialiphatic imidazoliniumquaternary ammonium salts, short chain C₁-C₄ dialiphatic imidazoliniumquaternary ammonium salts, long chain C₁₂-C₂₂ monoaliphatic benzylquaternary ammonium salts, long chain C₁₂-C₂₂dialkoyl(alkenoyl)-2-aminoethyl, short chain C₁-C₄ monoaliphatic benzylquaternary ammonium salts, short chain C₁-C₄ monohydroxyaliphaticquaternary ammonium salts. In certain embodiments, ditallow dimethylammonium methyl sulfate (DTDMAMS) may be used as a co-emulsifier.

The oil phase may comprise a photo-initiator at between about 0.05% andabout 10%, and in certain embodiments between about 0.2% and about 10%by weight of the oil phase. Lower amounts of photo-initiator allow lightto better penetrate the HIPE foam, which can provide for polymerizationdeeper into the HIPE foam. However, if polymerization is done in anoxygen-containing environment, there should be enough photo-initiator toinitiate the polymerization and overcome oxygen inhibition.Photo-initiators can respond rapidly and efficiently to a light sourcewith the production of radicals, cations, and other species that arecapable of initiating a polymerization reaction. The photo-initiatorsused in the present invention may absorb UV light at wavelengths ofabout 200 nanometers (nm) to about 800 nm, in certain embodiments about200 nm to about 350 nm. If the photo-initiator is in the oil phase,suitable types of oil-soluble photo-initiators include benzyl ketals,α-hydroxyalkyl phenones, α-amino alkyl phenones, and acylphospineoxides. Examples of photo-initiators include2,4,6-[trimethylbenzoyldiphosphine]oxide in combination with2-hydroxy-2-methyl-1-phenylpropan-1-one (50:50 blend of the two is soldby Ciba Speciality Chemicals, Ludwigshafen, Germany as DAROCUR® 4265);benzyl dimethyl ketal (sold by Ciba Geigy as IRGACURE 651);α-,α-dimethoxy-α-hydroxy acetophenone (sold by Ciba Speciality Chemicalsas DAROCUR® 1173); 2-methyl-1-[4-(methyl thio)phenyl]-2-morpholino-propan-1-one (sold by Ciba Speciality Chemicals asIRGACURE® 907); 1-hydroxycyclohexyl-phenyl ketone (sold by CibaSpeciality Chemicals as IRGACURE® 184);bis(2,4,6-trimethylbenzoyl)-phenylphosphineoxide (sold by CibaSpeciality Chemicals as IRGACURE 819); diethoxyacetophenone, and4-(2-hydroxyethoxy)phenyl-(2-hydroxy-2-methylpropyl)ketone (sold by CibaSpeciality Chemicals as IRGACURE® 2959); and Oligo[2-hydroxy-2-methyl-1-[4-(1-methylvinyl)phenyl]propanone] (sold byLamberti spa, Gallarate, Italy as ESACURE® KIP EM.

The dispersed aqueous phase of a HIPE can have water, and may also haveone or more components, such as initiator, photo-initiator, orelectrolyte, wherein in certain embodiments, the one or more componentsare at least partially water soluble.

One component of the aqueous phase may be a water-soluble electrolyte.The water phase may contain from about 0.2% to about 40%, in certainembodiments from about 2% to about 20%, by weight of the aqueous phaseof a water-soluble electrolyte. The electrolyte minimizes the tendencyof monomers, co-monomers, and cross-linkers that are primarily oilsoluble to also dissolve in the aqueous phase. Examples of electrolytesinclude chlorides or sulfates of alkaline earth metals such as calciumor magnesium and chlorides or sulfates of alkali earth metals such assodium. Such electrolyte can include a buffering agent for the controlof pH during the polymerization, including such inorganic counter-ionsas phosphate, borate, and carbonate, and mixtures thereof. Water solublemonomers may also be used in the aqueous phase, examples being acrylicacid and vinyl acetate.

Another component that may be present in the aqueous phase is awater-soluble free-radical initiator. The initiator can be present at upto about 20 mole percent based on the total moles of polymerizablemonomers present in the oil phase. In certain embodiments, the initiatoris present in an amount of from about 0.001 to about 10 mole percentbased on the total moles of polymerizable monomers in the oil phase.Suitable initiators include ammonium persulfate, sodium persulfate,potassium persulfate,2,2′-azobis(N,N′-dimethyleneisobutyramidine)dihydrochloride, and othersuitable azo initiators. In certain embodiments, to reduce the potentialfor premature polymerization which may clog the emulsification system,addition of the initiator to the monomer phase may be just after or nearthe end of emulsification.

Photo-initiators present in the aqueous phase may be at least partiallywater soluble and can have between about 0.05% and about 10%, and incertain embodiments between about 0.2% and about 10% by weight of theaqueous phase. Lower amounts of photo-initiator allow light to betterpenetrate the HIPE foam, which can provide for polymerization deeperinto the HIPE foam. However, if polymerization is done in anoxygen-containing environment, there should be enough photo-initiator toinitiate the polymerization and overcome oxygen inhibition.Photo-initiators can respond rapidly and efficiently to a light sourcewith the production of radicals, cations, and other species that arecapable of initiating a polymerization reaction. The photo-initiatorsused in the present invention may absorb UV light at wavelengths of fromabout 200 nanometers (nm) to about 800 nm, in certain embodiments fromabout 200 nm to about 350 nm, and in certain embodiments from about 350nm to about 450 nm. If the photo-initiator is in the aqueous phase,suitable types of water-soluble photo-initiators include benzophenones,benzils, and thioxanthones. Examples of photo-initiators include2,2′-Azobis[2-(2-imidazolin-2-yl)propane]dihydrochloride;2,2′-Azobis[2-(2-imidazolin-2-yl)propane]disulfate dehydrate;2,2′-Azobis(1-imino-1-pyrrolidino-2-ethylpropane)dihydrochloride;2,2′-Azobis[2-methyl-N-(2-hydroxyethyl)propionamide];2,2′-Azobis(2-methylpropionamidine)dihydrochloride;2,2′-dicarboxymethoxydibenzalacetone,4,4′-dicarboxymethoxydibenzalacetone,4,4′-dicarboxymethoxydibenzalcyclohexanone,4-dimethylamino-4′-carboxymethoxydibenzalacetone;and 4,4′-disulphoxymethoxydibenzalacetone. Other suitablephoto-initiators that can be used in the present invention are listed inU.S. Pat. No. 4,824,765 (Sperry et al.) issued Apr. 25, 1989.

In addition to the previously described components other components maybe included in either the aqueous or oil phase of a HIPE. Examplesinclude antioxidants, for example hindered phenolics, hindered aminelight stabilizers; plasticizers, for example dioctyl phthalate, dinonylsebacate; flame retardants, for example halogenated hydrocarbons,phosphates, borates, inorganic salts such as antimony trioxide orammonium phosphate or magnesium hydroxide; dyes and pigments;fluorescers; filler pieces, for example starch, titanium dioxide, carbonblack, or calcium carbonate; fibers; chain transfer agents; odorabsorbers, for example activated carbon particulates; dissolvedpolymers; dissolved oligomers; and the like.

The heterogeneous mass comprises enrobeable elements and discrete piecesof foam. The enrobeable elements may be a web or a portion of a web suchas, for example, nonwoven, a fibrous structure, an air-laid web, a wetlaid web, a high loft nonwoven, a needlepunched web, a hydroentangledweb, a fiber tow, a woven web, a knitted web, a flocked web, a spunbondweb, a layered spunbond/ melt blown web, a carded fiber web, a coformweb of cellulose fiber and melt blown fibers, a coform web of staplefibers and melt blown fibers, and layered webs that are layeredcombinations thereof.

The enrobeable elements may be, for example, conventional absorbentmaterials such as creped cellulose wadding, fluffed cellulose fibers,wood pulp fibers also known as airfelt, and textile fibers. Theenrobeable elements may also be fibers such as, for example, syntheticfibers, thermoplastic particulates or fibers, tricomponent fibers, andbicomponent fibers such as, for example, sheath/core fibers having thefollowing polymer combinations: polyethylene/polypropylene,polyethylvinyl acetate/polypropylene, polyethylene/polyester,polypropylene/polyester, copolyester/polyester, and the like. Theenrobeable elements may be any combination of the materials listed aboveand/or a plurality of the materials listed above, alone or incombination.

The enrobeable elements may be hydrophobic or hydrophilic. In anembodiment, the enrobeable elements may be treated to be madehydrophobic. In an embodiment, the enrobeable elements may be treated tobecome hydrophilic.

The constituent fibers of the heterogeneous mass can be comprised ofpolymers such as polyethylene, polypropylene, polyester, and blendsthereof. The fibers can be spunbond fibers. The fibers can be meltblownfibers. The fibers can comprise cellulose, rayon, cotton, or othernatural materials or blends of polymer and natural materials. The fiberscan also comprise a super absorbent material such as polyacrylate or anycombination of suitable materials. The fibers can be monocomponent,bicomponent, and/or biconstituent, non-round (e.g., capillary channelfibers), and can have major cross-sectional dimensions (e.g., diameterfor round fibers) ranging from 0.1-500 microns. The constituent fibersof the nonwoven precursor web may also be a mixture of different fibertypes, differing in such features as chemistry (e.g. polyethylene andpolypropylene), components (mono- and bi-), denier (micro denier and >20denier), shape (i.e. capillary and round) and the like. The constituentfibers can range from about 0.1 denier to about 100 denier.

The heterogeneous mass can be comprised of more than one nonwovenprecursor web. For example, the high internal phase emulsion is appliedto the top surface of the first nonwoven web by means of an extrusiondie in a horizontal configuration. A second nonwoven web can be appliedto the top surface of the previously extruded high internal phaseemulsion while in a horizontal configuration prior to the onset ofsolidification of the HIPE into a HIPE foam.

The above described structure creates a two nonwoven structure with HIPEfoam in between the nonwovens and enrobed elements at the interface ofHIPE foam and nonwoven, e.g. an absorbent stratum that is aheterogeneous mass comprising a first nonwoven having a first surfaceand a second surface and a second nonwoven. An open cell foam pieceenrobes a portion of the first nonwoven and a portion of the secondnonwoven. Alternatively, the second precursor web may be glued to thestratum heterogeneous mass after polymerization of the stratum.

It has been surprisingly found that by creating a heterogenous masslayer comprising open cell foam wherein at least a portion of one ormore open cell foam pieces is in contact with a substrate or layer ofenrobeable elements such as nonwoven fibers at both the top and bottomsurface of the piece along a vertical axis allows for the heterogeneousmass to be submitted through a formation means while maintaining thefluid connectivity of the heterogeneous mass layer and without leaving ameaningful buildup or residue on the formation means.

In one aspect, known absorbent web materials in an as-made state can beconsidered as being homogeneous throughout. Being homogeneous, the fluidhandling properties of the absorbent web material are not locationdependent, but are substantially uniform at any area of the web.Homogeneity can be characterized by density, basis weight, for example,such that the density or basis weight of any particular part of the webis substantially the same as an average density or basis weight for theweb. By the apparatus and method of the present invention, homogeneousfibrous absorbent web materials are modified such that they are nolonger homogeneous, but are heterogeneous, such that the fluid handlingand or mechanical properties of the web material are location dependent.Therefore, for the heterogeneous absorbent materials of the presentinvention, at discrete locations the density or basis weight of the webmay be substantially different than the average density or basis weightfor the web. The heterogeneous nature of the absorbent web of thepresent invention permits the negative aspects of either of permeabilityor capillarity to be minimized by rendering discrete portions highlypermeable and other discrete portions to have high capillarity.Likewise, the tradeoff between permeability and capillarity is managedsuch that delivering relatively higher permeability can be accomplishedwithout a decrease in capillarity. Likewise the heterogeneous nature ofthe absorbent web may also enable discrete bending, compression orstretch zones within the web.

In an embodiment, the heterogeneous mass may also include superabsorbentmaterial that imbibe fluids and form hydrogels. These materials aretypically capable of absorbing large quantities of body fluids andretaining them under moderate pressures and can be in either a fibrous,particulate or other physical form. The heterogeneous mass can includesuch materials dispersed in a suitable carrier such as cellulose fibersin the form of fluff or stiffened fibers or integrated within an AGMcontaining laminate.

The heterogeneous mass may include one or more types of fibers. Fibersincluded in the fibrous web may be thermoplastic particulates or fibers.The materials, and in particular thermoplastic fibers, can be made froma variety of thermoplastic polymers including polyolefins such aspolyethylene (e.g., PULPEX.RTM.) and polypropylene, polyesters,copolyesters, and copolymers of any of the foregoing.

Depending upon the desired characteristics, suitable thermoplasticmaterials include hydrophobic fibers that have been made hydrophilic,such as surfactant-treated or silica-treated thermoplastic fibersderived from, for example, polyolefins such as polyethylene orpolypropylene, polyacrylics, polyamides, polystyrenes, and the like. Thesurface of the hydrophobic thermoplastic fiber can be renderedhydrophilic by treatment with a surfactant, such as a nonionic oranionic surfactant, e.g., by spraying the fiber with a surfactant, bydipping the fiber into a surfactant or by including the surfactant aspart of the polymer melt in producing the thermoplastic fiber. Uponmelting and resolidification, the surfactant will tend to remain at thesurfaces of the thermoplastic fiber. Suitable surfactants includenonionic surfactants such as Brij 76 manufactured by ICI Americas, Inc.of Wilmington, Del., and various surfactants sold under thePegosperse.RTM. trademark by Glyco Chemical, Inc. of Greenwich, Conn.Besides nonionic surfactants, anionic surfactants can also be used.These surfactants can be applied to the thermoplastic fibers at levelsof, for example, from about 0.2 to about 1 g. per sq. of centimeter ofthermoplastic fiber.

Suitable thermoplastic fibers can be made from a single polymer(monocomponent fibers), or can be made from more than one polymer (e.g.,bicomponent fibers). The polymer comprising the sheath often melts at adifferent, typically lower, temperature than the polymer comprising thecore. As a result, these bicomponent fibers provide thermal bonding dueto melting of the sheath polymer, while retaining the desirable strengthcharacteristics of the core polymer.

Suitable bicomponent fibers for use in the present invention can includesheath/core fibers having the following polymer combinations:polyethylene/polypropylene, polyethylvinyl acetate/polypropylene,polyethylene/polyester, polypropylene/polyester, copolyester/polyester,and the like. Particularly suitable bicomponent thermoplastic fibers foruse herein are those having a polypropylene or polyester core, and alower melting copolyester, polyethylvinyl acetate or polyethylene sheath(e.g., DANAKLON.RTM., CELBOND.RTM. or CHISSO.RTM. bicomponent fibers).These bicomponent fibers can be concentric or eccentric. As used herein,the terms “concentric” and “eccentric” refer to whether the sheath has athickness that is even, or uneven, through the cross-sectional area ofthe bicomponent fiber. Eccentric bicomponent fibers can be desirable inproviding more compressive strength at lower fiber thicknesses. Suitablebicomponent fibers for use herein can be either uncrimped (i.e. unbent)or crimped (i.e. bent). Bicomponent fibers can be crimped by typicaltextile means such as, for example, a stuffer box method or the gearcrimp method to achieve a predominantly two-dimensional or “flat” crimp.

The length of bicomponent fibers can vary depending upon the particularproperties desired for the fibers and the web formation process.Typically, in an airlaid web, these thermoplastic fibers have a lengthfrom about 2 mm to about 12 mm long, preferably from about 2.5 mm toabout 7.5 mm long, and most preferably from about 3.0 mm to about 6.0 mmlong. The properties-of these thermoplastic fibers can also be adjustedby varying the diameter (caliper) of the fibers. The diameter of thesethermoplastic fibers is typically defined in terms of either denier(grams per 9000 meters) or decitex (grams per 10,000 meters). Suitablebicomponent thermoplastic fibers as used in an airlaid making machinecan have a decitex in the range from about 1.0 to about 20, preferablyfrom about 1.4 to about 10, and most preferably from about 1.7 to about7 decitex.

The compressive modulus of these thermoplastic materials, and especiallythat of the thermoplastic fibers, can also be important. The compressivemodulus of thermoplastic fibers is affected not only by their length anddiameter, but also by the composition and properties of the polymer orpolymers from which they are made, the shape and configuration of thefibers (e.g., concentric or eccentric, crimped or uncrimped), and likefactors. Differences in the compressive modulus of these thermoplasticfibers can be used to alter the properties, and especially the densitycharacteristics, of the respective thermally bonded fibrous matrix.

The heterogeneous mass can also include synthetic fibers that typicallydo not function as binder fibers but alter the mechanical properties ofthe fibrous webs. Synthetic fibers include cellulose acetate, polyvinylfluoride, polyvinylidene chloride, acrylics (such as Orlon), polyvinylacetate, non-soluble polyvinyl alcohol, polyethylene, polypropylene,polyamides (such as nylon), polyesters, bicomponent fibers, tricomponentfibers, mixtures thereof and the like. These might include, for example,polyester fibers such as polyethylene terephthalate (e.g., DACRON.RTM.and KODEL.RTM.), high melting crimped polyester fibers (e.g., KODEL.RTM.431 made by Eastman Chemical Co.) hydrophilic nylon (HYDROFIL.RTM.), andthe like. Suitable fibers can also hydrophilized hydrophobic fibers,such as surfactant-treated or silica-treated thermoplastic fibersderived from, for example, polyolefins such as polyethylene orpolypropylene, polyacrylics, polyamides, polystyrenes, polyurethanes andthe like. In the case of nonbonding thermoplastic fibers, their lengthcan vary depending upon the particular properties desired for thesefibers. Typically they have a length from about 0.3 to 7.5 cm,preferably from about 0.9 to about 1.5 cm. Suitable nonbondingthermoplastic fibers can have a decitex in the range of about 1.5 toabout 35 decitex, more preferably from about 14 to about 20 decitex.

However structured, the total absorbent capacity of the absorbent coreshould be compatible with the design loading and the intended use of themass. For example, when used in an absorbent article, the size andabsorbent capacity of the heterogeneous mass may be varied toaccommodate different uses such as incontinence pads, pantiliners,regular sanitary napkins, or overnight sanitary napkins.

The heterogeneous mass can also include other optional componentssometimes used in absorbent webs. For example, a reinforcing scrim canbe positioned within the respective layers, or between the respectivelayers, of the heterogeneous mass.

The heterogeneous mass comprising open-cell foam pieces produced fromthe present invention may be used as an absorbent core or a portion ofan absorbent core in absorbent articles, such as feminine hygienearticles, for example pads, pantiliners, and tampons; wound dressing;disposable diapers; incontinence articles, for example pads, adultdiapers; homecare articles, for example wipes, pads, towels; and beautycare articles, for example pads, wipes, and skin care articles, such asused for pore cleaning. The absorbent structure having a topsheet and/ora secondary topsheet integrated into a heterogeneous mass layer havingopen-cell foam pieces may be used in absorbent articles such as femininehygiene articles, for example pads, pantiliners, and tampons; wounddressings; disposable diapers; incontinence articles, for example pads,adult diapers; homecare articles, for example wipes, pads, towels; andbeauty care articles, for example pads, wipes, and skin care articles,such as used for pore cleaning. A diaper may be an absorbent article asdisclosed in U.S. patent application Ser. No. 13/428,404, filed on Mar.23, 2012.

The absorbent core structure may be used as an absorbent core for anabsorbent article. In such an embodiment, the absorbent core can berelatively thin, less than about 5 mm in thickness, or less than about 3mm, or less than about 1 mm in thickness. Cores having a thickness ofgreater than 5 mm are also contemplated herein. Thickness can bedetermined by measuring the thickness at the midpoint along thelongitudinal centerline of the pad by any means known in the art fordoing while under a uniform pressure of 0.25 psi. The absorbent core cancomprise absorbent gelling materials (AGM), including AGM fibers, bloodgelling agents (e.g. chitosan), quaternary salts or combinations thereofas is known in the art.

The heterogeneous mass layer may be formed or cut to a shape, the outeredges of which define a periphery.

In an embodiment, the heterogeneous mass may be used as a topsheet foran absorbent article. The heterogeneous mass may be combined with anabsorbent core or may only be combined with a backsheet.

In an embodiment, the heterogeneous mass may be combined with any othertype of absorbent layer or non-absorbent layer such as, for example, alayer of cellulose, a layer comprising superabsorbent gelling materials,a layer of absorbent airlaid fibers, a nonwoven layer, or a layer ofabsorbent foam, or combinations thereof. Other absorbent layers notlisted are contemplated herein.

In an embodiment, the open-cell foam pieces are in the form of stripes.The stripes may be formed during the formation of the heterogeneous massor by formation means after polymerization. The stripes may run alongthe longitudinal length of the heterogeneous mass layer, along thelateral length of the heterogeneous mass layer, or a combination of boththe longitudinal length and the lateral length. The stripes may runalong a diagonal to either the longitudinal length or the lateral lengthof the heterogeneous mass layer. The stripes are separated by canals.

Formation means known for deforming a generally planar fibrous web intoa three-dimensional structure are utilized in the present invention tomodify as-made absorbent materials into absorbent materials havingrelatively higher permeability without a significant correspondingdecrease in capillary pressure. Using formation means, one may create anabsorbent structure by providing a first fibrous web material, whereinthe first fibrous web material is a heterogeneous mass comprising one ormore open cell foam pieces; providing a second fibrous web material;providing a pair of rolls forming a nip through which said first fibrousweb material and second fibrous web material can be processed, said pairof rolls being selected from the processes consisting of ring rolling,SELF, micro-SELF, nested SELF, rotary knife aperturing, hot pin, 3Dembossing, SAN, and embossed stabilized formation; and deforming boththe first fibrous web material and the second fibrous web. The secondfibrous web may be absorbent.

Formation means may comprise a pair of inter-meshing rolls, typicallysteel rolls having inter-engaging ridges or teeth and grooves. However,it is contemplated that other means for achieving formation can beutilized, such as the deforming roller and cord arrangement disclosed inUS 2005/0140057 published Jun. 30, 2005. Therefore, all disclosure of apair of rolls herein is considered equivalent to a roll and cord, and aclaimed arrangement reciting two inter-meshing rolls is consideredequivalent to an inter-meshing roll and cord where a cord functions asthe ridges of a mating inter-engaging roll. In one embodiment, the pairof intermeshing rolls of the instant invention can be considered asequivalent to a roll and an inter-meshing element, wherein theinter-meshing element can be another roll, a cord, a plurality of cords,a belt, a pliable web, or straps. Likewise, other known formationtechnologies, such as creping, necking/consolidation, corrugating,embossing, button break, hot pin punching, and the like are believed tobe able to produce absorbent materials having some degree of relativelyhigher permeability without a significant corresponding decrease incapillary pressure. Formation means utilizing rolls include “ringrolling”, a “SELF” or “SELF'ing” process, in which SELF stands forStructural Elastic Like Film, as “micro-SELF”, and “rotary knifeaperturing” (RKA); as described in U.S. Pat. No. 7,935,207 Zhao et al.,granted May 3, 2011. The formation means may be one of the formationmeans described in U.S. Pat. No. 7,682,686 (Curro et al.) granted onMar. 23, 2010 or U.S. Pat. No. 7,648,752 (Hoying et al.) granted on Jan.19, 2010. Suitable processes for constructing tufts are described inU.S. Pat. Nos. 7,172,801; 7,838,099; 7,754,050; 7,682,686; 7,410,683;7,507,459; 7,553,532; 7,718,243; 7,648,752; 7,732,657; 7,789,994;8,728,049; and 8,153,226. Formation means may also include Nested “SELF”as described below and in U.S. pstent application Ser. No. 14/844459filed on Sep. 3, 2015. Formation means may also include hot pin,Selective Aperturing a Nonwoven (SAN) described in U.S. Pat. No.5,628,097, 3D embossing and embossed stabilized formation as describedin U.S. Patent Application No. 62/458,051 filed Feb. 13, 2017.

Referring to FIG. 1 there is shown in an apparatus and method for makingweb 1. The apparatus 100 comprises a pair of intermeshing rolls 174 and176, each rotating about an axis A, the axes A being parallel in thesame plane. Roll 174 comprises a plurality of ridges 172 andcorresponding grooves 108 which extend unbroken about the entirecircumference of roll 174. Roll 176 is similar to roll 174, but ratherthan having ridges that extend unbroken about the entire circumference,roll 176 comprises a plurality of rows of circumferentially-extendingridges that have been modified to be rows of circumferentially-spacedteeth 110 that extend in spaced relationship about at least a portion ofroll 176. The individual rows of teeth 110 of roll 176 are separated bycorresponding grooves 112. In operation, rolls 174 and 176 intermeshsuch that the ridges 172 of roll 174 extend into the grooves 112 of roll176 and the teeth 110 of roll 176 extend into the grooves 108 of roll174. The intermeshing is shown in greater detail in the cross sectionalrepresentation of FIG. 2, discussed below. Both or either of rolls 174and 176 can be heated by means known in the art such as by using hot oilfilled rollers or electrically-heated rollers.

In FIG. 1, the apparatus 100 is shown in a preferred configurationhaving one patterned roll, e.g., roll 176, and one non-patterned groovedroll 174. However, in certain embodiments it may be preferable to usetwo patterned rolls 176 having either the same or differing patterns, inthe same or different corresponding regions of the respective rolls.Such an apparatus can produce webs with tufts 6 protruding from bothsides of the web 1.

The method of making a web 1 in a commercially viable continuous processis depicted in FIG. 1. Web 1 is made by mechanically deforming precursorwebs, such as first and second precursor webs, 180 and 21 that can eachbe described as generally planar and two dimensional prior to processingby the apparatus shown in FIG. 1. By “planar” and “two dimensional” ismeant simply that the webs start the process in a generally flatcondition relative to the finished web 1 that has distinct,out-of-plane, Z-direction three-dimensionality due to the formation oftufts 6. “Planar” and “two-dimensional” are not meant to imply anyparticular flatness, smoothness or dimensionality.

The process and apparatus of the present invention is similar in manyrespects to a process described in U.S. Pat. No. 5,518,801 entitled “WebMaterials Exhibiting Elastic-Like Behavior” and referred to insubsequent patent literature as “SELF” webs, which stands for“Structural Elastic-like Film”. However, there are significantdifferences between the apparatus and process of the present inventionand the apparatus and process disclosed in the '801 patent, and thedifferences are apparent in the respective webs produced thereby. Asdescribed below, the teeth 110 of roll 176 have a specific geometryassociated with the leading and trailing edges that permit the teeth toessentially “punch” through the precursor webs 180, 21 as opposed to, inessence, deforming the web. In a two layer laminate web 1 the teeth 110urge fibers from precursor webs 180 and 21 out-of-plane by the teeth 110pushing the fibers 8 through to form tufts 6. Therefore, a web 1 canhave tufts 6 comprising loose fiber ends 18 and/or “tunnel-like” tufts 6of looped, aligned fibers 8 extending away from the surface 13 of side3, unlike the “tent-like” rib-like elements of SELF webs which each havecontinuous side walls associated therewith, i.e., a continuous“transition zone,” and which do not exhibit interpenetration of onelayer through another layer.

Precursor webs 180 and 21 are provided either directly from theirrespective web making processes or indirectly from supply rolls (neithershown) and moved in the machine direction to the nip 116 ofcounter-rotating intermeshing rolls 174 and 176. The precursor webs arepreferably held in a sufficient web tension so as to enter the nip 16 ina generally flattened condition by means well known in the art of webhandling. As each precursor web 180, 21 goes through the nip 116 theteeth 110 of roll 176 which are intermeshed with grooves 108 of roll 174simultaneously urge portions of precursor webs 180 and 21 out of theplane to form tufts 6. In one embodiment, teeth 110 in effect “push” or“punch” fibers of first precursor web 180 through second precursor web21. In another embodiment teeth 110 in effect “push” or “punch” fibersof both first and second precursor webs 180 and 21 out of plane to formtufts 6.

As the tip of teeth 110 push through first and second precursor webs180, 21 the portions of the fibers of first precursor web 180 (and, insome embodiments, second precursor web 21) that are orientedpredominantly in the CD across teeth 110 are urged by the teeth 110 outof the plane of first precursor web 180. Fibers can be urged out ofplane due to fiber mobility, or they can be urged out of plane by beingstretched and/or plastically deformed in the Z-direction. Portions ofthe precursor webs urged out of plane by teeth 110 results in formationof tufts 6 on first side 3 of web 1. Fibers of precursor webs 180 and 21that are predominantly oriented generally parallel to the longitudinalaxis L, i.e., in the MD as shown in FIG. 3, are simply spread apart byteeth 110 and remain substantially in their original, randomly-orientedcondition. This is why the looped fibers 8 can exhibit the unique fiberorientation in embodiments such as the one shown in FIGS. 3-4, which isa high percentage of fibers of each tuft 6 having a significant or majorvector component parallel to the transverse axis T of tuft 6.

It can be appreciated by the forgoing description that when web 1 ismade by the apparatus and method of the present invention that theprecursor webs 180, 21 can possess differing material properties withrespect to the ability of the precursor webs to elongate before failure,e.g., failure due to tensile stresses. In one embodiment, a nonwovenfirst precursor web 180 can have greater fiber mobility and/or greaterfiber elongation characteristics relative to second precursor web 21,such that the fibers thereof can move or stretch sufficiently to formtufts 6 while the second precursor web 21 ruptures, i.e., does notstretch to the extent necessary to form tufts. In another embodiment,second precursor web 21 can have greater fiber mobility and/or greaterfiber elongation characteristics relative to first precursor web 180,such that both first and second precursor webs 180 and 21 form tufts 6.In another embodiment, second precursor web 21 can have greater fibermobility and/or greater fiber elongation characteristics relative tofirst precursor web 180, such that the fibers of second precursor web 21can move or stretch sufficiently to form tufts 6 while the firstprecursor web 180 ruptures, i.e., does not stretch to the extentnecessary to form tufts.

The degree to which the fibers of nonwoven precursor webs are able toextend out of plane without plastic deformation can depend upon thedegree of inter-fiber bonding of the precursor web. For example, if thefibers of a nonwoven precursor web are only very loosely entangled toeach other, they will be more able to slip by each other (i.e., to moverelative to adjacent fibers by reptation) and therefore be more easilyextended out of plane to form tufts. On the other hand, fibers of anonwoven precursor web that are more strongly bonded, for example byhigh levels of thermal point bonding, hydroentanglement, or the like,will more likely require greater degrees of 14795C 31 plasticdeformation in extended out-of-plane tufts. Therefore, in oneembodiment, one precursor web 180 or 21 can be a nonwoven web havingrelatively low inter-fiber bonding, and the other precursor web 180 or21 can be a nonwoven web having relatively high inter-fiber bonding,such that the fibers of one precursor web can extend out of plane, whilethe fibers of the other precursor web cannot.

In one embodiment, for a given maximum strain (e.g., the strain imposedby teeth 110 of apparatus 100), it is beneficial that second precursorweb 21 actually fail under the tensile loading produced by the imposedstrain. That is, for the tufts 6 comprising only, or primarily, fibersfrom first precursor web 180 to be disposed on the first side 3 of web1, second precursor web 21 must have sufficiently low fiber mobility (ifany) and/or relatively low elongation-to-break such that it locally(i.e., in the area of strain) fails in tension, thereby producingopenings 4 through which tufts 6 can extend.

In another embodiment it is beneficial that second precursor web 21deform or stretch in the region of induced strain, and does not fail,such that tuft 6 includes portions of second precursor web 21.

In one embodiment second precursor web 21 has an elongation to break inthe range of 1%-5%. While the actual required elongation to breakdepends on the strain to be induced to form web. 1, it is recognizedthat for most embodiments, second precursor web 21 can exhibit a webelongation-to-break of 6%, 7%, 8%, 9%, 10%, or more. It is alsorecognized that actual elongation-to-break can depend on the strainrate, which, for the apparatus shown in FIG. 1 is a function of linespeed. Elongation to break of webs used in the present invention can bemeasured by means known in the art, such as by standard tensile testingmethods using standard tensile testing apparatuses, such as thosemanufactured by Instron, MTS, Thwing-Albert, and the like.

Relative to first precursor web 180, second precursor web 21 can havelower fiber mobility (if any) and/or lower elongation-to-break (i.e.,elongation-to-break of individual fibers, or, if a film,elongation-to-break of the film) such that, rather than extendingout-of-plane to the extent of the tufts 6, second precursor web 21 failsin tension under the strain produced by the formation of tufts 6, e.g.,by the teeth 110 of apparatus 100. In one embodiment, second precursorweb 21 exhibits sufficiently low elongation-to-break relative to firstprecursor web 180 such that flaps 7 of opening 4 only extend slightlyout-of-plane, if at all, relative to tufts 6. In general, forembodiments in which tufts 6 comprise primarily fibers from firstprecursor web 180, it is believed that second precursor web 21 shouldhave an elongation to break of at least 10% less than the firstprecursor web 180, preferably at least 30% less, more preferably atleast 50% less, and even more preferably at least about 100% less thanthat of first precursor web 180. Relative elongation to break values ofwebs used in the present invention can be measured by means known in theart, such as by standard tensile testing methods using standard tensiletesting apparatuses, such as those manufactured by Instron, MTS,Thwing-Albert, and the like.

In one embodiment second precursor web 21 can comprise substantially allMD-oriented fibers, e.g., tow fibers, such that there are substantiallyno fibers oriented in the CD. For such an embodiment of web 1 the fibersof second precursor web 21 can simply separate at the opening 4 throughwhich tufts 6 extend. In this embodiment, therefore, second precursorweb 21 need not have any minimum elongation to break, since failure orrupture of the material is not the mode of forming opening 4.

The number, spacing, and size of tufts 6 can be varied by changing thenumber, spacing, and size of teeth 110 and making correspondingdimensional changes as necessary to roll 176 and/or roll 174. Thisvariation, together with the variation possible in precursor webs 180,21 permits many varied webs 1 having varied fluid handling propertiesfor use in a disposable absorbent article. As described more fullybelow, a web 1 comprising a nonwoven/film first precursor web/secondprecursor web combination can also be used as a component in disposableabsorbent articles. However, even better results are obtained in anonwoven/nonwoven precursor web/second precursor web combination whereinfibers from both webs contribute to tufts 6.

FIG. 2 shows in cross section a portion of the intermeshing rolls 174and 176 and ridges 172 and teeth 110. As shown teeth 110 have a toothheight TH (note that TH can also be applied to ridge height; in apreferred embodiment tooth height and ridge height are equal), and atooth-to-tooth spacing (or ridge-to-ridge spacing) referred to as thepitch P. As shown, depth of engagement E is a measure of the level ofintermeshing of rolls 174 and 176 and is measured from tip of ridge 172to tip of tooth 110. The depth of engagement E, tooth height TH, andpitch P can be varied as desired depending on the properties ofprecursor webs 180, 21 and the desired characteristics of web 1. Forexample, in general, the greater the level of engagement E, the greaterthe necessary elongation or fiber-to-fiber mobility characteristics thefibers of portions of the precursor webs intended to form tufts mustpossess. Also, the greater the density of tufts 6 desired (tufts 6 perunit area of web 1), the smaller the pitch should be, and the smallerthe tooth length TL and tooth distance TD should be, as described below.

FIG. 5 shows one embodiment of a roll 176 having a plurality of teeth110 useful for making a web 1 from a nonwoven first precursor web 180having a basis weight of between about 60 gsm and 100 gsm, preferablyabout 80 gsm and a polyolefinic film (e.g., polyethylene orpolypropylene) second precursor web 21 having a density of about0.91-0.94 and a basis weight of about 180 gsm.

An enlarged view of teeth 110 is shown in FIG. 6. In this embodiment ofroll 176 teeth 110 have a uniform circumferential length dimension TLmeasured generally from the leading edge LE to the trailing edge TE atthe tooth 111 of about 1.25 mm and are uniformly spaced from one anothercircumferentially by a distance TD of about 1.5 mm. For making aterry-cloth web 1 from web 1 having a total basis weight in the range ofabout 60 to about 100 gsm, teeth 110 of roll 176 can have a length TLranging from about 0.5 mm to about 10 mm and a spacing TD from about 0.5mm to about 10 mm, a tooth height TH ranging from about 0.5 mm to about10 mm, and a pitch P between about 1 mm (0.040 inches) and about 5 mm(0.1800 inches). Depth of engagement E can be from about 0.5 mm to about10 mm (up to a maximum equal to tooth height TH). Of course, E, P, TH,TD and TL can be varied independently of each other to achieve a desiredsize, spacing, and area density of tufts 6 (number of tufts 6 per unitarea of web 1).

As shown in FIG. 6, each tooth 110 has a tip 111, a leading edge LE anda trailing edge TE. The tooth tip 111 is elongated and has a generallylongitudinal orientation, corresponding to the longitudinal axes L oftufts 6 and discontinuities 16. It is believed that to get the tufted,looped tufts 6 of the web 1 that can be described as being terrycloth-like, the LE and TE should be very nearly orthogonal to the localperipheral surface 1180 of roll 176. As well, the transition from thetip 111 and LE or TE should be a sharp angle, such as a right angle,having a sufficiently small radius of curvature such that teeth 110 pushthrough second precursor web 21 at the LE and TE. Without being bound bytheory, it is believed that having relatively sharply angled tiptransitions between the tip of tooth 110 and the LE and TE permits theteeth 110 to punch through precursor webs 180, 21 “cleanly”, that is,locally and distinctly, so that the first side 3 of the resulting web 1can be described as “tufted” rather than “deformed.” When so processed,the web 1 is not imparted with any particular elasticity, beyond whatthe precursor webs 180 and 21 may have possessed originally.

At higher line speeds, i.e., relatively higher rates of processing ofthe web through the nip of rotating rolls 174 and 176, like materialscan exhibit very different structures for tufts 6. The tuft 6 shown inFIG. 7 is similar in structure to the tuft shown in FIG. 4 but exhibitsa very different structure, a structure that appears to be typical ofspunbond nonwoven first precursor webs 180 processed to form tufts 6 atrelatively high speeds, i.e., at high strain rates. Typical of thisstructure is broken fibers between the proximal portion, i.e., base 7,of tufts 6 and the distal portion, i.e., the top 31, of tuft 6, and whatappears to be a “mat” 19 of fibers at the top of the tuft 6. Mat 19comprises and is supported at the top of tufts 6 by unbroken, loopedfibers 8, and also comprises portions of broken fibers 11 that are nolonger integral with first precursor web 180. That is, mat 19 comprisesfiber portions which were formerly integral with precursor web 180 butwhich are completely detached from precursor web 180 after processing atsufficiently high line speeds, e.g., 30 meters per minute line speed inthe process described with reference to FIG. 1.

Therefore, from the above description, it is understood that in oneembodiment web 1 can be described as being a laminate web formed byselective mechanical deformation of at least a first and secondprecursor webs, at least the first precursor web being a nonwoven web,the laminate web having a first garment-facing, side, the firstgarment-facing side comprising the second precursor web and a pluralityof discrete tufts, each of the discrete tufts comprising fibers integralwith but extending from the first precursor web and fibers neitherintegral with nor extending from the first precursor web.

As shown in FIG. 8, after tufts 6 are formed, tufted precursor web 21travels on rotating roll 104 to nip 117 between roll 104 and a firstbonding roll 156. Bonding roll 156 can facilitate a number of bondingtechniques. For example, bonding roll 156 can be a heated steel rollerfor imparting thermal energy in nip 117, thereby melt-bonding adjacentfibers of tufted web 21 at the distal ends (tips) of tufts 6. Bondingroll 156 can also facilitate thermal bonding by means of pressure only,or use of heat and pressure. In one embodiment, for example, nip 117 canbe set at a width sufficient to compress the distal ends of tufts 6,which at high rates of processing can cause thermal energy transfer tothe fibers, which can then reflow and bond.

Depending on the type of bonding being facilitated, bonding roll 156 canbe a smooth, steel surface, or a relatively soft, flexible surface. In apreferred embodiment, as discussed in the context of a preferred webbelow, bonding roll 156 is a heated roll designed to impart sufficientthermal energy to tufted web 21 so as to thermally bond adjacent fibersof the distal ends of tufts 6. Thermal bonding can be by melt-bondingadjacent fibers directly, or by melting an intermediate thermoplasticagent, such as polyethylene powder, which in turn, adheres adjacentfibers. Polyethylene powder can be added to precursor web 20 for suchpurposes.

First bonding roll 156 can be heated sufficiently to melt or partiallymelt fibers 8 or 18 at the distal ends 3 of tufts 6. The amount of heator heat capacity necessary in first bonding roll 156 depends on the meltproperties of the fibers of tufts 6 and the speed of rotation of roll104. The amount of heat necessary in first bonding roll 156 also dependson the pressure induced between first bonding roll 156 and tips of teeth110 on roll 104, as well as the degree of melting desired at distal ends3 of tufts 6. In one embodiment, bonding roll 156 can provide sufficientheat and pressure to not only melt bond fibers at the distal ends 3 oftufts 6, but also cut through the bonded portion so as to, in effect,cut through the end of tuft 6. In such an embodiment, the tuft isdivided into two portions, but is not longer looped. In one embodiment,pressure alone can cause the looped portion of the tuft to be cutthrough, thereby rendering the tufts 6 to be un-looped tufts of fiberfree ends. Other methods known in the art, such as use of a spinningwire brush wheel can also be utilized to cut the loops of looped fibersto form un-looped tufts.

In one embodiment, first bonding roll 156 is a heated steel cylindricalroll, heated to have a surface temperature sufficient to melt-bondadjacent fibers of tufts 6. First bonding roll can be heated by internalelectrical resistance heaters, by hot oil, or by any other means knownin the art for making heated rolls. First bonding roll 156 can be drivenby suitable motors and linkages as known in the art. Likewise, firstbonding roll can be mounted on an adjustable support such that nip 117can be accurately adjusted and set.

Nested “SELF” relates to a method that includes making a fibrousmaterials by a method comprising the steps of: a) providing at least oneprecursor nonwoven web; b) providing an apparatus comprising a pair offorming members comprising a first forming member (a “male” formingmember) and a second forming member (a “female” forming member); and c)placing the precursor nonwoven web(s) between the forming members andmechanically deforming the precursor nonwoven web(s) with the formingmembers. The forming members have a machine direction (MD) orientationand a cross-machine direction (CD) orientation.

The first and second forming members can be plates, rolls, belts, or anyother suitable types of forming members. In the embodiment of theapparatus 200 shown in FIG. 9, the first and second forming members 182and 190 are in the form of non-deformable, meshing, counter-rotatingrolls that form a nip 188 therebetween. The precursor web(s) is/are fedinto the nip 188 between the rolls 182 and 190. Although the spacebetween the rolls 182 and 190 is described herein as a nip, as discussedin greater detail below, in some cases, it may be desirable to avoidcompressing the precursor web(s) to the extent possible.

First Forming Member.

The first forming member (such as “male roll”) 182 has a surfacecomprising a plurality of first forming elements which comprisediscrete, spaced apart male forming elements 112. The male formingelements are spaced apart in the machine direction and in thecross-machine direction.

As shown in FIG. 10, the male forming elements 112 have a base 186 thatis joined to (in this case is integral with) the first forming member182, a top 184 that is spaced away from the base, and side walls (or“sides”) 120 that extend between the base 186 and the top 184 of themale forming elements. The male elements 112 may also have a transitionportion or region 122 between the top 184 and the side walls 120. Themale elements 112 also have a plan view periphery, and a height H₁ (thelatter being measured from the base 186 to the top 184). The discreteelements on the male roll may have a top 184 with a relatively largesurface area (e.g., from about 1 mm to about 10 mm in width, and fromabout 1 mm to about 20 mm in length) for creating a wide deformation.The male elements 112 may, thus, have a plan view aspect ratio (ratio oflength to width) that ranges from about 1:1 to about 10:1. For thepurpose of determining the aspect ratio, the larger dimension of themale elements 112 will be consider the length, and the dimensionperpendicular thereto will be considered to be the width of the maleelement. The male elements 112 may have any suitable configuration.

The base 186 and the top 184 of the male elements 112 may have anysuitable plan view configuration, including but not limited to: arounded diamond configuration as shown in FIGS. 9 and 10, an Americanfootball-like shape, triangle, circle, clover, a heart-shape, teardrop,oval, or an elliptical shape. The configuration of the base 186 and theconfiguration of the top 184 of the male elements 112 may be in any ofthe following relationships to each other : the same, similar, ordifferent. The top 184 of the male elements 112 can be flat, rounded, orany configuration therebetween.

The transition region or “ transition ” 122 between the top 184 and theside walls 120 of the male elements 112 may also be of any suitableconfiguration. The transition 122 can be in the form of a sharp edge (asshown in FIG. 10C) in which case there is zero, or a minimal radiuswhere the side walls 120 and the top 184 of the male elements meet. Thatis, the transition 122 may be substantially angular, sharp,non-radiused, or non-rounded. In other embodiments, such as shown inFIG. 10, the transition 122 between the top 184 and the side walls 120of the male elements 112 can be radiused, or alternatively beveled.Suitable radiuses include, but are not limited to: zero (that is, thetransition forms a sharp edge), 0.01 inch (about 0.25 mm), 0.02 inch(about 0.5 mm), 0.03 inch (about 0.76 mm), 0.04 inch (aboutl mm) (or any0.01 inch increment above 0.01 inch), up to a fully rounded male elementas shown in FIG. 10D.

In some cases, it may be desired to roughen the surface of all, or aportion, of the male elements 112. The surface of the male elements 112can be roughened in any suitable manner. The surface of the maleelements 112 can be roughened, for example, by : media blasting (thatis, roughened with shot or “shot blasted”); wet blasting (roughed withwater jets); plasma coating, machining, or knurling (i.e., pressureembossing of surface of first forming member) ; or combinations of thesame. The roughened configuration and characteristics of the maleelements 112 will depend on the type of process used to roughen thesame. The roughening will typically provide at least the top 184 of atleast some of the male elements 112 with greater than or equal to twodiscrete first surface texture elements protruding therefrom.

Second Forming Member.

As shown in FIG. 9, the second forming member (such as “female roll”)190 has a surface 124 having a plurality of cavities or recesses 114therein. The recesses 114 are aligned and configured to receive the maleforming elements 112 therein. Thus, the male forming elements 112 matewith the recesses 114 so that a single male forming element 112 fitswithin the periphery of a single recess 114, and at least partiallywithin the recess 114 in the z-direction. The recesses 114 have a planview periphery 126 that is larger than the plan view periphery of themale elements 112. As a result, the recess 114 on the female roll maycompletely encompass the discrete male element 112 when the rolls 182and 190 are intermeshed. The recesses 114 have a depth D₁ shown in FIG.11. In some cases, the depth D₁ of the recesses may be greater than theheight H₁ of the male forming elements 112.

The recesses 114 have a plan view configuration, side walls 128, a topedge or rim 134 around the upper portion of the recess where the sidewalls 128 meet the surface 124 of the second forming member 190, and abottom edge 130 around the bottom 132 of the recesses where the sidewalls 128 meet the bottom 132 of the recesses.

The recesses 114 may have any suitable plan view configuration providedthat the recesses can receive the male elements 112 therein. Therecesses 114 may have a similar plan view configuration as the maleelements 112. In other cases, some or all of the recesses 114 may have adifferent plan view configuration from the male elements 112.

The top edge or rim 134 around the upper portion of the recess where theside walls 128 meet the surface 124 of the second forming member 190 mayhave any suitable configuration. The rim 134 can be in the form of asharp edge (as shown in FIG. 11) in which case there is zero, or aminimal radius where the side walls 128 of the recesses meet the surfaceof the second forming member 190. That is, the rim 134 may besubstantially angular, sharp, non-radiused, or non-rounded. In otherembodiments, such as shown in FIG. 11A, the rim 134 can be radiused, oralternatively beveled. Suitable radiuses include, but are not limited to: zero (that is, form a sharp edge), 0.01 inch (about 0.25 mm), 0.02inch (about 0.5 mm), 0.03 inch (about 0.76 mm), 0.04 inch (about 1 mm)(or any 0.01 inch increment above 0.01 inch) up to a fully rounded landarea between some or all of the side walls 128 around each recess 114.The bottom edge 130 of the recesses 114 may be sharp or rounded.

In some cases, it may be desired to roughen the surface of all, or aportion, of the second forming member 190 and/or recesses 114 byproviding the same with a plurality of discrete second surface textureelements 142 thereon. The surface of the second forming member 190and/or recesses 114 can be roughened in any of the manners describedabove for roughening the surface of the male elements 112. This mayprovide the surface of the second forming member 190 and/or recesses 114with second surface texture elements 142 (and/or valleys 144, raisedareas 146, and microscale texture 148 as shown in FIG. 10G) having thesame or similar properties as the first surface texture elements 140 onthe male elements 112. Thus, the second surface texture elements 142 canbe distributed on the surface of the second forming member 190 in aregular pattern or a random pattern.

The depth of engagement (DOE) is a measure of the level of intermeshingof the forming members. As shown in FIG. 11, the DOE is measured fromthe top 184 of the male elements 112 to the (outermost) surface 124 ofthe female forming member 114 (e.g., the roll with recesses). The DOEmay, for example, range from at least about 1.5 mm, or less, to about 5mm, or more. In certain embodiments, the DOE may be between about 2.5 mmto about 5 mm, alternatively between about 3 mm and about 4 mm.

As shown in FIG. 11, there is a clearance, C, between the sides 120 ofthe male elements 112 and the sides (or side walls) 128 of the recesses114. The clearances and the DOE's are related such that largerclearances can permit higher DOE's to be used. The clearance, C, betweenthe male and female roll may be the same, or it may vary around theperimeter of the male element 112. For example, the forming members canbe designed so that there is less clearance between the sides of themale elements 112 and the adjacent side walls 128 of the recesses 114than there is between the side walls at the end of the male elements 112and the adjacent side walls of the recesses 114. In other cases, theforming members can be designed so that there is more clearance betweenthe sides 120 of the male elements 112 and the adjacent side walls 128of the recesses 114 than there is between the side walls at the end ofthe male elements 112 and the adjacent side walls of the recesses. Instill other cases, there could be more clearance between between theside wall on one side of a male element 112 and the adjacent side wallof the recess 114 than there is between the side wall on the opposingside of the same male element 112 and the adjacent side wall of therecess. For example, there can be a different clearance at each end of amale element 112; and/or a different clearance on each side of a maleelement 112. Clearances can range from about 0.005 inches (about 0.1 mm)to about 0.1 inches (about 2.5 mm).

The precursor nonwoven web 30 is placed between the forming members 182and 190. The precursor nonwoven web can be placed between the formingmembers with either side of the precursor web (first surface 34 orsecond surface 36) facing the first forming member, male forming member182. For convenience of description, the second surface 36 of theprecursor nonwoven web will be described herein as being placed incontact with the first forming member 182. Of course, in otherembodiments, the second surface 36 of the precursor nonwoven web can beplaced in contact with the second forming member 190.)

The Nested SELF process can create wells that are larger in diameter(ie. >1 mm). The bottom of the well can be pushed downward with littleto no fracturing of the material within the well. The Nested SELFprocess could also comprise a roll with ridges and grooves, with theridges being broken about the circumference by discrete regions wherethe ridges have been removed. These discrete regions span two or moreadjacent teeth and form a shape, such as a circle, ellipse, square,octagon, etc.

According to an embodiment, an absorbent article can comprise a liquidpervious topsheet. The topsheet suitable for use herein can comprisewovens, non-wovens, apertured webs or not aperture webs, and/orthree-dimensional webs of a liquid impermeable polymeric film comprisingliquid permeable apertures. The topsheet may be a laminate. The topsheetmay have more than one layer. The topsheet may comprise nonwoven fibersselecteted from the group consisting of meltblown, nanofibers,bicomponent fibers, and combinations thereof. The topsheet for useherein can be a single layer or may have a multiplicity of layers. Forexample, the wearer-facing and contacting surface can be provided by afilm material having apertures which are provided to facilitate liquidtransport from the wearer facing surface towards the absorbentstructure. Such liquid permeable, apertured films are well known in theart. They provide a resilient three-dimensional fibre-like structure.Such films have been disclosed in detail for example in U.S. Pat. Nos.3,929,135, 4,151,240, 4,319,868, 4,324,426, 4,343,314, 4,591,523,4,609,518, 4,629,643, 4,695,422 or WO 96/00548.

The topsheet and/or the secondary topsheet may comprise a nonwovenmaterial. The nonwoven materials of the present invention can be made ofany suitable nonwoven materials (“precursor materials”). The nonwovenwebs can be made from a single layer, or multiple layers (e.g., two ormore layers). If multiple layers are used, they can be comprised of thesame type of nonwoven material, or different types of nonwovenmaterials. In some cases, the precursor materials may be free of anyfilm layers.

The fibers of the nonwoven precursor material(s) can be made of anysuitable materials including, but not limited to natural materials,synthetic materials, and combinations thereof.

Suitable natural materials include, but are not limited to cellulose,cotton linters, bagasse, wool fibers, silk fibers, etc. Cellulose fiberscan be provided in any suitable form, including but not limited toindividual fibers, fluff pulp, drylap, liner board, etc. Suitablesynthetic materials include, but are not limited to nylon, rayon, andpolymeric materials. Suitable polymeric materials include, but are notlimited to: polyethylene (PE), polyester, polyethylene terephthalate(PET), polypropylene (PP), and co-polyester. Suitable synthetic fibersmay have submicron diameters, thereby being nanofibers, such as Nufibersor be between 1 and 3 microns such as meltblown fibers or may be oflarger diameter. In some embodiments, however, the nonwoven precursormaterials can be either substantially, or completely free, of one ormore of these materials. For example, in some embodiments, the precursormaterials may be substantially free of cellulose, and/or exclude papermaterials. In some embodiments, one or more precursor materials cancomprise up to 100% thermoplastic fibers. The fibers in some cases may,therefore, be substantially non-absorbent. In some embodiments, thenonwoven precursor materials can be either substantially, or completelyfree, of tow fibers.

The precursor nonwoven materials can comprise any suitable types offibers. Suitable types of fibers include, but are not limited to:monocomponent, bicomponent, and/or biconstituent, non-round (e.g.,shaped fibers (including but not limited to fibers having a trilobalcross-section) and capillary channel fibers). The fibers can be of anysuitable size. The fibers may, for example, have major cross-sectionaldimensions (e.g., diameter for round fibers) ranging from 0.1-500microns. Fiber size can also be expressed in denier, which is a unit ofweight per length of fiber. The constituent fibers may, for example,range from about 0.1 denier to about 100 denier. The constituent fibersof the nonwoven precursor web(s) may also be a mixture of differentfiber types, differing in such features as chemistry (e.g., PE and PP),components (mono- and bi-), shape (i.e. capillary channel and round) andthe like.

The nonwoven precursor webs can be formed from many processes, such as,for example, air laying processes, wetlaid processes, meltblowingprocesses, spunbonding processes, and carding processes. The fibers inthe webs can then be bonded via spunlacing processes, hydroentangling,calendar bonding, through-air bonding and resin bonding. The nonwovenprecursor web or nonwoven web may be aperture with a process such asoverbonding or pre-aperturing. Some of such individual nonwoven webs mayhave bond sites 46 where the fibers are bonded together.

In the case of spunbond webs, the web may have a thermal point bond 46pattern that is not highly visible to the naked eye. For example, densethermal point bond patterns are equally and uniformly spaced aretypically not highly visible. After the material is processed throughthe mating male and female rolls, the thermal point bond pattern isstill not highly visible. Alternatively, the web may have a thermalpoint bond pattern that is highly visible to the naked eye. For example,thermal point bonds that are arranged into a macro-pattern, such as adiamond pattern, are more visible to the naked eye. After the materialis processed through the mating male and female rolls, the thermal pointbond pattern is still highly visible and can provide a secondary visibletexture element to the material.

The basis weight of nonwoven materials is usually expressed in grams persquare meter (gsm). The basis weight of a single layer nonwoven materialcan range from about 8 gsm to about 100 gsm, depending on the ultimateuse of the material 30. For example, the topsheet of atopsheet/acquisition layer laminate or composite may have a basis weightfrom about 8 to about 40 gsm, or from about 8 to about 30 gsm, or fromabout 8 to about 20 gsm. The acquisition layer may have a basis weightfrom about 10 to about 120 gsm, or from about 10 to about 100 gsm, orfrom about 10 to about 80 gsm. The basis weight of a multi-layermaterial is the combined basis weight of the constituent layers and anyother added components. The basis weight of multi-layer materials ofinterest herein can range from about 20 gsm to about 150 gsm, dependingon the ultimate use of the material 30. The nonwoven precursor webs mayhave a density that is between about 0.01 and about 0.4 g/cm³ measuredat 0.3 psi (2 KPa).

The precursor nonwoven webs may have certain desired characteristics.The precursor nonwoven web(s) each have a first surface, a secondsurface, and a thickness. The first and second surfaces of the precursornonwoven web(s) may be generally planar. It is typically desirable forthe precursor nonwoven web materials to have extensibility to enable thefibers to stretch and/or rearrange into the form of the protrusions. Ifthe nonwoven webs are comprised of two or more layers, it may bedesirable for all of the layers to be as extensible as possible.Extensibility is desirable in order to maintain at least some non-brokenfibers in the sidewalls around the perimeter of the protrusions. It maybe desirable for individual precursor webs, or at least one of thenonwovens within a multi-layer structure, to be capable of undergoing anapparent elongation (strain at the breaking force, where the breakingforce is equal to the peak force) of greater than or equal to about oneof the following amounts: 100% (that is double its unstretched length),110%, 120%, or 130% up to about 200%. It is also desirable for theprecursor nonwoven webs to be capable of undergoing plastic deformationto ensure that the structure of the deformations is “set” in place sothat the nonwoven web will not tend to recover or return to its priorconfiguration.

Materials that are not extensible enough (e.g., inextensible PP) mayform broken fibers around much of the perimeter of the deformation, andcreate more of a “hanging chad” (i.e., the cap of the protrusions may beat least partially broken from and separated from the rest of theprotrusion. The area on the sides of the protrusion where the fibers arebroken is designated with reference number.

When the fibers of a nonwoven web are not very extensible, it may bedesirable for the nonwoven to be underbonded as opposed to optimallybonded. A thermally bonded nonwoven web's tensile properties can bemodified by changing the bonding temperature. A web can be optimally orideally bonded, underbonded, or overbonded. Optimally or ideally bondedwebs are characterized by the highest breaking force and apparentelongation with a rapid decay in strength after reaching the breakingforce. Under strain, bond sites fail and a small amount of fibers pullout of the bond site. Thus, in an optimally bonded nonwoven, the fibers38 will stretch and break around the bond sites 46 when the nonwoven webis strained beyond a certain point. Often there is a small reduction infiber diameter in the area surrounding the thermal point bond sites 46.Underbonded webs have a lower breaking force and apparent elongationwhen compared to optimally bonded webs, with a slow decay in strengthafter reaching the breaking force. Under strain, some fibers will pullout from the thermal point bond sites 46. Thus, in an underbondednonwoven, at least some of the fibers 38 can be separated easily fromthe bond sites 46 to allow the fibers 38 to pull out of the bond sitesand rearrange when the material is strained. Overbonded webs also have alowered breaking force and elongation when compared to optimally bondedwebs, with a rapid decay in strength after reaching the breaking force.The bond sites look like films and result in complete bond site failureunder strain.

When the nonwoven web comprises two or more layers, the different layerscan have the same properties, or any suitable differences in propertiesrelative to each other. In one embodiment, the nonwoven web can comprisea two layer structure that is used in an absorbent article. Forconvenience, the precursor webs and the material into which they areformed will generally be referred to herein by the same referencenumbers. As described above, one of the layers, a second layer, canserve as the topsheet of the absorbent article, and the first layer canbe an underlying layer (or sub-layer) and serve as an acquisition layer.The acquisition layer receives liquids that pass through the topsheetand distributes them to underlying absorbent layers. In such a case, thetopsheet may be less hydrophilic than sub-layer(s), which may lead tobetter dewatering of the topsheet. In other embodiments, the topsheetcan be more hydrophilic than the sub-layer(s). In some cases, the poresize of the acquisition layer may be reduced, for example via usingfibers with smaller denier or via increasing the density of theacquisition layer material, to better dewater the pores of the topsheet.

The second nonwoven layer that may serve as the topsheet can have anysuitable properties. The second nonwoven layer may be absorbent.Properties of interest for the second nonwoven layer, when it serves asa topsheet, in addition to sufficient extensibility and plasticdeformation may include uniformity and opacity. As used herein,“uniformity” refers to the macroscopic variability in basis weight of anonwoven web. As used, herein, “opacity” of nonwoven webs is a measureof the impenetrability of visual light, and is used as visualdetermination of the relative fiber density on a macroscopic scale. Asused herein, “opacity” of the different regions of a single nonwovendeformation is determined by taking a photomicrograph at 20Xmagnification of the portion of the nonwoven containing the deformationagainst a black background. Darker areas indicate relatively loweropacity (as well as lower basis weight and lower density) than whiteareas.

Several examples of nonwoven materials suitable for use as the secondnonwoven layer 30B include, but are not limited to: spunbondednonwovens; carded nonwovens; and other nonwovens with high extensibility(apparent elongation in the ranges set forth above) and sufficientplastic deformation to ensure the structure is set and does not havesignificant recovery. One suitable nonwoven material as a topsheet for atopsheet/acquisition layer composite structure may be an extensiblespunbonded nonwoven comprising polypropylene and polyethylene. Thefibers can comprise a blend of polypropylene and polyethylene, or theycan be bi-component fibers, such as a sheath-core fiber withpolyethylene on the sheath and polypropylene in the core of the fiber.Another suitable material is a bi-component fiber spunbonded nonwovencomprising fibers with a polyethylene sheath and apolyethylene/polypropylene blend core.

The first nonwoven layer that may, for example, serve as the acquisitionlayer can have any suitable properties. Properties of interest for thefirst nonwoven layer, in addition to sufficient extensibility andplastic deformation may include uniformity and opacity. If the firstnonwoven layer serves as an acquisition layer, its fluid handlingproperties must also be appropriate for this purpose. Such propertiesmay include: permeability, porosity, capillary pressure, caliper, aswell as mechanical properties such as sufficient resistance tocompression and resiliency to maintain void volume. Suitable nonwovenmaterials for the first nonwoven layer when it serves as an acquisitionlayer include, but are not limited to: spunbonded nonwovens; through-airbonded (“TAB”) carded nonwoven materials; spunlace nonwovens;hydroentangled nonwovens; and, resin bonded carded nonwoven materials.Of course, the composite structure may be inverted and incorporated intoan article in which the first layer serves as the topsheet and thesecond layer serves as an acquisition layer. In such cases, theproperties and exemplary methods of the first and second layersdescribed herein may be interchanged.

The layers of a two or more layered nonwoven web structure can becombined together in any suitable manner. In some cases, the layers canbe unbonded to each other and held together autogenously (that is, byvirtue of the formation of deformations therein). For example, bothprecursor webs 30A and 30B contribute fibers to deformations in a“nested” relationship that joins the two precursor webs together,forming a multi-layer web without the use or need for adhesives orthermal bonding between the layers. In other embodiments, the layers canbe joined together by other mechanisms. If desired an adhesive betweenthe layers, ultrasonic bonding, chemical bonding, resin or powderbonding, thermal bonding, or bonding at discrete sites using acombination of heat and pressure can be selectively utilized to bondcertain regions or all of the precursor webs. In addition, the multiplelayers may be bonded during processing, for example, by carding onelayer of nonwoven onto a spunbond nonwoven and thermal point bonding thecombined layers. In some cases, certain types of bonding between layersmay be excluded. For example, the layers of the present structure may benon-hydroentangled together.

If adhesives are used, they can be applied in any suitable manner orpattern including, but not limited to: slots, spirals, spray, andcurtain coating. Adhesives can be applied in any suitable amount orbasis weight including, but not limited to between about 0.5 and about30 gsm, alternatively between about 2 and about 5 gsm. Examples ofadhesives could include hot melt adhesives, such as polyolefins andstyrene block copolymers.

A certain level of adhesive may reduce the level of fuzz on the surfaceof the nonwoven material even though there may be a high percentage ofbroken fibers as a result of the deformation process. Glued dual-layerlaminates produced as described herein are evaluated for fuzz. Themethod utilizes a Martindale Abrasion Tester, based upon ASTM D4966-98.After abrading the samples, they are graded on a scale of 1-10 based onthe degree of fiber pilling (1=no fiber pills; 10=large quantity andsize of fiber pills). The protrusions are oriented away from the abraderso the land area in between the depressions is the primary surfaceabraded. Even though the samples may have a significant amount of fiberbreakage (greater than 25%, sometimes greater than 50%) in the sidewalls of the protrusions/depressions, the fuzz value may be low (around2) for several different material combinations, as long as the layers donot delaminate during abrasion. Delamination is best prevented by gluebasis weight, for example a glue basis weight greater than 3 gsm, andglue coverage.

When the precursor nonwoven web comprises two or more layers, it may bedesirable for at least one of the layers to be continuous, such as inthe form of a web that is unwound from a roll.

In some embodiments, each of the layers can be continuous. Inalternative embodiments, one or more of the layers can be continuous,and one or more of the layers can have a discrete length. The layers mayalso have different widths. For example, in making a combined topsheetand acquisition layer for an absorbent article, the nonwoven layer thatwill serve as the topsheet may be a continuous web, and the nonwovenlayer that will serve as the acquisition layer may be fed into themanufacturing line in the form of discrete length (for example,rectangular, or other shaped) pieces that are placed on top of thecontinuous web. Such an acquisition layer may, for example, have alesser width than the topsheet layer. The layers may be combinedtogether as described above. Nonwoven webs and materials are oftenincorporated into products, such as absorbent articles, at highmanufacturing line speeds. Such manufacturing processes can applycompressive and shear forces on the nonwoven webs that may damagecertain types of three-dimensional features that have been purposefullyformed in such webs. In addition, in the event that the nonwovenmaterial is incorporated into a product (such as a disposable diaper)that is made or packaged under compression, it becomes difficult topreserve the three-dimensional character of some types of priorthree-dimensional features after the material is subjected to suchcompressive forces.

The nonwoven material can comprise a composite of two or more nonwovenmaterials that are joined together. In such a case, the fibers andproperties of the first layer will be designated accordingly (e.g., thefirst layer is comprised of a first plurality of fibers), and the fibersand properties of the second and subsequent layers will be designatedaccordingly (e.g., the second layer is comprised of a second pluralityof fibers). In a two or more layer structure, there are a number ofpossible configurations the layers may take following the formation ofthe deformations therein. These will often depend on the extensibilityof the nonwoven materials used for the layers. It is desirable that atleast one of the layers have deformations which form protrusions asdescribed herein in which, along at least one cross-section, the widthof the cap of the protrusions is greater than the width of the baseopening of the deformations. For example, in a two layer structure whereone of the layers will serve as the topsheet of an absorbent article andthe other layer will serve as an underlying layer (such as anacquisition layer), the layer that has protrusions therein may comprisethe topsheet layer. The layer that most typically has a bulbous shapewill be the one which is in contact with the male forming member duringthe process of deforming the web.

The heterogeneous mass may be combined with the topsheet, a secondarytopsheet, or the both using formation means. A group of fibers, or infact, a portion of the whole topsheet is physically inserted into theheterogeneous mass so that within a single X-Y plane, a fiber from thetopsheet, secondary topsheet, or both, is in direct contact with one ormore fibers of the heterogeneous mass.

It has been surprisingly found that by placing a fibrous topsheet or afibrous secondary topsheet, or both a fibrous topsheet and a secondarytopsheet through a formation means process with a heterogeneous mass,one can create one or more “wells” instead of an aperture. Wells aredistinguished from apertures and channels in that the outer surface ofthe wells includes one or more fibers from the group of fibers beingintegrated with the core without densifying the fibers that form thewell. The “wells” may provide improved drainage of the topsheet throughthe secondary topsheet to the core comprising the heterogeneous mass.Use of wells may lead to various benefits including high fluid bridgingbetween layers for reduced pooling of fluid at layer interfaces.Additionally, the “wells” may provide a higher capillarity workpotential gradient to draw fluid away from topsheet and into the corecompared to traditional absorbent articles, such as, for example, from100 mJ/m² to 8000 mJ/m² within 0.5 mm, or 0.25 mm, or within 0.15 mmrather than current topsheets which have a gradient of 100 mJ/m² to 1000mJ/m² over about 2 mm, or about 1.5 mm, or about 1 mm of distance. Thecapillarity work potential gradient may be between 500 mJ/m² and 7000mJ/m² within 0.15 mm, such as, for example, between 1000 mJ/m² and 7000mJ/m², between 1500 mJ/m² and 6500 mJ/m² , between 2000 mJ/m² and 6000mJ/m² , between 2500 mJ/m² and 5000 mJ/m² , such as, for example 500,1000, 1500, 2000, 2500, 3000, 3500, 4000, 4500, 5000, 5500, 6000, 6500,7000, 7500 mJ/m². Capillarity cascade relates to the change incapillarity as fluid moves from one layer to another layer within anabsorbent structure. The thinner the materials are in each layer or thethinner the total thickness is through all layers, and the higher thedifference in capillarity work potential between each layer, the higherthe capillarity work potential gradient or capillarity cascade is withinthe absorbent structure. Traditional absorbent structures simply cannotachieve a capillarity work potential gradient across such a smalldistance in either the z-direction or within an x-y plane containingmultiple layers of absorbent materials.

Without being bound by theory, it is believed that the integrated layersincluding a topsheet and/or a secondary topsheet with a heterogeneousmass that has a high capillary absorbent intertwined within the layerprovides multiple surprising advantageous. Amongst these advantages14795C 47 may be, without limitation, 1. The ability to create bridgingbetween the topsheet and the absorbent core for the purpose of absorbingcomplex liquids, 2. The ability to create a capillarity cascade withinthe topsheet to core system that allows form the moving of complexliquids into the high capillarity absorbent, 3. An absorbent systemhaving an absorbent core and a topsheet that may conform to complex bodyshapes and dynamic movement, 4. An absorbent system having an absorbentcore and a topsheet that has improved tactile feel.

Without being bound by theory, it is believed that the “wells” mayprovide improved drainage of the topsheet through the secondary topsheetto the core comprising the fibrous web. Specifically, the wells allowfor improved drainage via the wells from the topsheet to the absorbentcore when fluid is placed on the topsheet. The number of wells in anabsorbent structure is set according to the pattern chosen during theformation means.

The wells are identified and can be seen within the same XY plane as theintegrated layers. A group of fibers from the topsheet are integratedinto the heterogeneous mass layer which comprises open cell foam. Thegroup of fibers may be between 10 and 10,000 fibers per grouping, suchas, for example, 10 fibers per grouping of fibers, 20 fibers pergrouping of fibers, 30 fibers per grouping of fibers, 40 fibers pergrouping of fibers, 50 fibers per grouping of fibers, 60 fibers pergrouping of fibers, 70 fibers per grouping of fibers, 80 fibers pergrouping of fibers, 90 fibers per grouping of fibers, 100 fibers pergrouping, 400 fibers per grouping, 500 fibers per grouping, 1,000 fibersper grouping, 2,000 fibers per grouping, 3,000 fibers per grouping,4,000 fibers per grouping, 5,000 fibers per grouping, 6,000 fibers pergrouping, 7,000 fibers per grouping, 8,000 fibers per grouping, or 9,000fibers per grouping. One or more grouping of fibers may be in directcontact. At least one of the grouping of fibers has a portion that isthe external surface of a portion of a well.

A grouping of fibers may be inserted into the X-Y plane of both the STSand core such that it penetrates between 10% to 100% of the core layer,such as, 20%, 30%, 40%, 50%, 60%, 70%, 80%, or 90%. This is unliketraditional needlepunching that only places a few fibers down into atraditional core. Further, the group of fibers of the topsheet, or agroup of fibers of the secondary topsheet and the fibers of theheterogeneous mass are in close proximity to each other within this X-Yplane, on the order of 0.01 mm to 0.5 mm distance, such as, for example0.05 mm, 0.1 mm, 0.15 mm, 0.2 mm, 0.25 mm, 0.3 mm, 0.35 mm, 0.4 mm, or0.45 mm.

The areas of the topsheet adjacent to the wells, the topsheet, Secondarytopsheet, and core are in much closer or more intimate contact. Withoutbeing bound by theory, it is believed that the open cell foam mayprovide a resiliency or upward pressure against the topsheet.Traditional cores would likely disintegrate and/or would have no upwardresiliency if they were placed through a 14795C 48 similar formationmeans transformation process. Further, full foam layer cores woulddisintegrate and/or tear if placed through a similar process.

As previously discussed, the “wells” may provide a higher capillaritywork potential gradient to draw fluid away from topsheet and into thecore compared to traditional absorbent articles, such as, for example,from 100 mJ/m² to 80,000 mJ/m² within 0.5 mm, or 0.25 mm, or within 0.15mm rather than current topsheets which have a gradient of 100 mJ/m² to1000 mJ/m² over about 2 mm, or about 1.5 mm, or about 1 mm of distance.The absorbent core structure may exhibit a capillary cascade of between,for example, 100 mJ/m² to 80,000 mJ/m² within 0.5 mm; 1,000 mJ/m² to70,000 mJ/m² within 0.5 mm; 3,000 mJ/m² to 70,000 mJ/m² within 0.5 mm;5,000 mJ/m² to 60,000 mJ/m² within 0.5 mm; 10,000 mJ/m² to 50,000 mJ/m²within 0.5 mm; 20.000 mJ/m² to 40,000 mJ/m² within 0.5 mm; 100 mJ/m² to80,000 mJ/m² within 0.25 mm; 1,000 mJ/m² to 70,000 mJ/m² within 0.25 mm;3,000 mJ/m² to 70,000 mJ/m² within 0.25 mm; 5,000 mJ/m² to 60,000 mJ/m²within 0.25 mm; 10,000 mJ/m² to 50,000 mJ/m² within 0.25 mm; 20.000mJ/m² to 40,000 mJ/m² within 0.25 mm; 100 mJ/m² to 80,000 mJ/m² within0.15 mm; 1,000 mJ/m² to 70,000 mJ/m² within 0.15 mm; 3,000 mJ/m² to70,000 mJ/m² within 0.15 mm; 5,000 mJ/m² to 60,000 mJ/m² within 0.15 mm;10,000 mJ/m² to 50,000 mJ/m² within 0.15 mm; or 20.000 mJ/m² to 40,000mJ/m² within 0.15 mm.

Additionally, the wells allow for the absorbent structure to exhibit acapillarity cascade along not only the vertical plane but also along theX-Y plane. Unlike other structures that may exhibit differentcapillarity profiles in the vertical direction versus within a plane,the absorbent structure having an integrated topsheet with aheterogeneous mass layer comprising wells creates a structure where thecapillarity cascade is present within a plane. This is due to theintegration of the groups of fibers from the topsheet through theheterogeneous mass.

The system absorbent structure having an integrated topsheet in aheterogeneous mass stratum provides surprising improvements in fluidacquisition. Specifically, the absorbent structure allows for a driertopsheet as measured via an NMR mouse method. The absorbent structurehaving an integrated topsheet, and/or integrated secondary topsheet, andheterogeneous mass exhibits a residual fluid left on a topsheet that isless than 1 ml/cm², such as for example, 0.75 ml/cm², 0.5 ml/cm² , 0.4ml/cm² , 0.3 ml/cm² ,0.2 ml/cm², or 0.1m1/cm², as measured via the NMRmouse method. The absorbent structure having an integrated topsheet,and/or integrated secondary topsheet, and heterogeneous mass exhibits aresidual fluid left in the top 1mm of the absorbent article that is lessthan 1 ml/mm, such as for example, 0.75 ml/ mm, 0.5 ml/ mm, 0.4 ml/mm,0.3 ml/ mm,0.2 ml/ mm, or 0.1ml/mm, as measured via the NMR Mousemethod. Further, due to the use of wells in the integrated system, thesystem exhibits a negative slope of fluid removal from the topsheet asmeasured via the NMR Mouse method.

Further, fluid bridging is greatly enhanced via close integration of allthree layers by a formation means. The resulting benefit is an ansorbentstructure that is able to take in complex fluids at a rapid rate whileproviding an unmatched dryness. This is unlike previous fast topsheets,such as hydrophilically coated topsheets that may be fast but remain wetor have high-rewet values.

The integrated layer system may be quantified by the speed of moisturewithdrawal from topsheet after fluid insult as measured by the NMR Mousetechnique, the amount of residual moisture in the topsheet layer asmeasured by the NMR Mouse technique, or the rewet values of the pad asmeasured by the traditional rewet method.

The unique structure of this product can be measured by the amount oftopsheet that is below or in-plane with the core as measured by NMRMouse. The integrated absorbent structure may exhibit a residual fluidamount in the top 1 mm of the integrated topsheet core sample of lessthan 0.6 ml, such as, for example, between 0.0 ml and 0.5 ml, such as,less than 0.4 ml, less than 0.3 ml, less than 0.2 ml, or between 0 and0.1 ml according to the NMR Mouse method.

As shown in FIGS. 27 to 29, a variety of patterns could be used. Thepatterns include zones. Zones are areas exhibiting one of either avisual pattern, a topography, an absorption rate or property, a bendingparameter, a compression modulus, a resiliency, a stretch parameter or acombination thereof. The visual pattern may be any known geometric shapeor pattern that is visual and can be conceived by the human mind. Thetopography may be any known pattern that is measurable and can beconceived by the human mind. Zones may be repeated or discrete. Zonesmay be orthogonal shapes and continuities that provide a visualappearance. The use of zones allows for tailoring of the fluid handlingand mechanical properties of and within the pad. The integratedabsorbent structure may have one or more visual patterns including zonesalong one of either the longitudinal or lateral axis of the integratedlayers. The integrated layers may have two or more zones comprising oneor more visual patterns. The two or more zones may be separated by aboundary. The boundary may be a topographical boundary, a mechanicalboundary, a visual boundary, a fluid handling property boundary, or acombination thereof, provided that the boundary is not a densificationof the absorbent core structure. The boundary property may be distinctfrom the two zones adjacent to the boundary. The absorbent structure mayhave a perimeter boundary that exhibits a different property than theone or more adjacent zones to the boundary.

It has also been surprisingly found that using formation means tointegrate the topsheet, secondary topsheet, and the heterogeneous massresults in an improved flexibility of the pad (as measured by bunchedcompression. This is unlike traditional systems that become stiffer dueto welding, glues, embossing, or when they improve capillarity throughdensification.

Further, by integrating a topsheet and/or a secondary topsheet with afibrous web having high capillarity absorbents intertwined by eitherenrobement of the fibers or by using absorbent fibers, one can create anabsorbent product that has a high degree of integration (as demonstratedby dryness of topsheet), low rewet due to strong capillarity close tothe topsheet, and improved flexibility of the pad (as measured by thebunched compression test). This is unlike prior approaches to improvefluid bridging such as welding, gluing or needlepunching the topsheet tothe Secondary Topsheet which often leads to a potential increase in thestiffness of the resulting product or a loss in flexibility of thecombined layer versus the individual layers.

Further, the integrated topsheet and/or secondary topsheet with theheterogeneous mass delivers unique patterns that enable shapingdynamically without loss of structural integrity. The unique patternsmay be leveraged such that they selectively deform some of the webenabling multiple bending modes for conforming to complex bodily shapeswithout meaningful degradation of the structural integrity of theabsorbent product. Further, by designing the bending points in theabsorbent product using formation means, one may create a product thathas a better fit. The better fit is exemplified when the product isplaced in contact with the spacing in the gluteal groove. Further, byenabling the product to have three dimensional topography, the absorbentproduct may bend and stretch to complex shapes and various surfacetopographies to be closer to the body of the user. Bending may bedifferent for different sections.

The bunched compression method is a multi-axis bending test that isexecuted on product or core samples. When formation means is executed ona traditional layered core or a foam layer, in-use properties rapidlydegrade or create product/core integrity issues. The ratio of the peakforce to wet recovery energy communicates the balance betweenflexibility and shape stability of the product. The lower the peak forcethe more flexibility the product/material has when bending andconforming to her complex shape.

The absorbent structure may be deformed in the z direction with lowcompressive force while nevertheless preserving simultaneous the abilityto conform and flow with complex bodily movements. As discussed above,the topsheet and/or secondary topsheet integrated with a heterogeneousmass having a high capillarity absorbent has been found to impartcurved, stretchable contours that can flow with the body withoutsignificant force to deform while not displacing her tissuesaggressively. Further, the absorbent structure lacks strongdensification, sharp tears, or shredding as seen with traditionalcellulose based materials. Strong densification, 14795C 51 sharp tears,and shredding may provide sharp contour which lead to a reduction incomfort and tactile softness. This property is exhibited using theZ-compressibility and the BC/Kawabata test methods.

Increased product flexibility may directly lead to improved comfort bythe user. Increased flexibility allows for the product to follow thetopography of the user's body and thereby may create better contactbetween the article and the body. Further, improved flexibility leads toa better usage experience because the product behaves more like agarment and may follow the contours of the body through dynamic motions.Another vector that improves overall comfort for the user is the levelof cushion that the absorbent article may provide. Due to the directcontact with the body, increasing the cushion of the product andremoving any rough surfaces leads to an improved tactile feel andcomfort for the user.

A dynamic flexibility range and sustained product shape is given to theproduct by the specified ratio of peak to wet recovery of less than150gf/N*mm and greater than 30 gf/N*mm. Conformance is also communicatedto the user thru initial interaction with the pad the “cushiness” incaliper, stiffness and resiliency properties of the absorbent product inthe thru thickness direction. In market products have demonstrated aconsumer desirable stiffness gradient that signals a premium qualitysoftness and product conformance in the product thru thicknessdirection. The quilted and/or pillowy nature of particular formationmeans patterns with the desireable stiffness gradient providesimultaneously a ZD direction cushiness that is desirable as well asactive body cleaning locations that enhance the comfort experience in away that the topography of traditional in market core systems cannot.

Table 1. Description of materials, material layers, integrated layers,suppliers, basis weight, caliper, capillarity work potential, andcapillarity gradients.

TABLE 1 Description of materials, material layers, integrated layers,suppliers, basis weight, caliper, capillarity work potential, andcapillarity gradients. Distance CWP Basis Topsheet to Gradient MATERIALWeight Caliper CWP Absorbent (mJ/, ∧2)/ DESCRIPTIONS (gsm) (mm) (mJ/m∧2)Layer, mm mm Prior Art 1 Always Ultra N/A N/A N/A N/A N/A Market ProductComposition: Topsheet 25 0.75 130 Secondary 77 0.77 330 0.75 267Topsheet Absorbent Core 180 1.15 860 0.77 688 Prior Art 2 InfinityMarket N/A N/A N/A N/A N/A Product Composition: Topsheet 28 0.38 115Foam Layer 1 188 1.5 1300 0.38 3118 Foam Layer 2 188 0.6 7000 1.5 3800Inventions 3a, 3b, 3c, 4a, 4b, 4c Nonwoven 50 1.1 125 TopsheetHeterogenous 224 1.8 7870 0.5 15490 Mass Stratum 0.25 30980 0.15 51633Inventions 3d, 4d Nonwoven 28 0.38 115 Topsheet BiCO Heterogenous 2241.8 7870 0.5 15510 Mass Stratum 0.25 31020 0.15 51700

As shown in Table 1, Prior Art 1 is an Always Ultra Market product,Prior Art 2 is an Always Infinity product, Inventions 3a, 3b, 3c, 4a,4b, and 4c are a nonwoven topsheet with a heterogeneous mass stratum,and Inventions 3d and 4d are a nonwoven BiCo topsheet with aheterogeneous mass stratum. As shown by the data in Table 1, thecombination of different material layers and the integration of thoselayers can be used to create a high capillarity work potential gradientacross an absorbent structure, or said another way, an optimizedcapillarity cascade. For instance, a capillarity gradient between twolayers within an Always Ultra pad can be determined by comparing thecapillarity of the first layer, e.g. topsheet (130 mJ/m²) and thecapillarity of the second layer, e.g. STS (330 mJ/m²), and then dividingthe capillarity work potential by the distance the fluid must travel. Inthis case, the capillarity difference, 200 mJ/m² is divided by thedistance between the two top surfaces (e.g. 0.75 mm distance), giving acapillarity gradient of about 267 mJ/m²/mm. The distance between the topsurface of the STS and the top surface of the core is 0.77 mm and thedifference in capillarity work potential between the two materials is530mJ/m². Thus, the capillarity gradient between these two layers isabout 688mJ/m²/mm. For a measure of the overall performance of anabsorbent article, the difference between the capillarity work potentialof the topsheet to the storage layer, or core, should be evaluated. Foran Always Ultra pad, the capillarity of the storage layer or core is 860mJ/m², so the capillarity difference between the topsheet and core is730 mJ/m². The overall system has a total fluid travel distance of 1.52mm and a capillarity work potential difference of 730 mJ/m², so thecapillarity gradient of this absorbent system is about 480 mJ/m²/mm.

With an absorbent product made with similar nonwoven topsheet (125 mJ/m²capillarity work potential, 1.1 mm caliper), no STS, and a heterogeneousmass core (7870 mJ/m²) wherein both layers have been integrated throughformation means or solid state formation, the capillarity gradient issignificantly stronger because the distance between the two layers hasalso been significantly reduced via solid state formation. The actualdistance the fluid has to travel from the top surface of the topsheet tothe top of the heterogeneous mass core has been reduced to between 0.15mm and 0.5 mm. If the distance the fluid has to travel is reduced to0.5mm, the capillarity gradient is now 15490 mJ/m²/mm. In the situationwhere surface wells as previously described have been formed by solidstate formation, the distance between the topsheet and core may be asless than or equal to 0.25 mm, and the fluid can travel in either the Zdirection or within multiple X-Y planes due to the topsheet andheterogeneous mass layer being closely integrated within the wells. Inthis case, the capillarity gradient may be as high as 30,980 mJ/m²/mm.

Therefore, one embodiment of the present invention is an absorbentproduct having a capillarity gradient between the topsheet and storagelayer that may be greater than 8,000 mJ/m²/mm, such as for example,between 8,000 mJ/m²/mm and 60,000 mJ/m²/mm, such as for example, 14,000mJ/m²/mm, or 20,000 mJ/m²/mm, or 28,000 mJ/m²/mm, or 36,000 mJ/m²/mm, or50,000 mJ/m²/mm, or 60,000mJ/m²/mm.

Table 2A and 2B. Examples from combining different materials, cores,topsheet integration, types of integration and resulting mechanicalcharacteristics.

TABLE 2A Bunched Compression 1st Cycle Wet Recovery Ratio Dry PeakTopsheet Dry Peak Energy 5th Over Wet Examples Integration? Force, gfCycle, N · mm Energy Prior Art 1 None 200 1.2 167 Prior Art 2 None 1212.6 47 Invention 3a None 350 3.5 100 Invention 3b RIPS-DB1 257 1.9 135Invention 3c Jellyfish 171 1.94 88 Invention 3d Diamond 319 1.8 177Invention 4a None 98 2.2 45 Invention 4b RIPS-DB1 74 1.5 49 Invention 4cJellyfish 75 1.4 54 Invention 4d Diamond 78 1.0 78

TABLE 2B Z-Compression Slope (Newton/mm)@ Percent Compression of InitialCaliper Kawabata Testing Compressive Kawabata Dry, MD Energy Examples(gf*cm{circumflex over ( )}2/cm) 13% 25% 38% 50% Resiliency (N · mm)Prior Art 1 1.74 2.04 5.04 14.63 71.26 77% 21.0 Prior Art 2 10.65 5.499.30 9.78 17.82 40% 16.8 Invention 3a 11.65 4.30 7.57 13.82 20.18 40%25.2 Invention 3b 3.82 5.29 10.03 13.25 17.32 40% 13.0 Invention 3c 1.495.28 14.07 25.96 45.09 43% 22.2 Invention 3d 2.77 6.29 10.44 13.11 18.4240% 20.5 Invention 4a 6.55 4.30 7.57 13.82 20.18 40% 25.2 Invention 4b2.92 5.29 10.03 13.25 17.32 40% 13.0 Invention 4c 1.88 5.28 14.07 25.9645.09 43% 22.2 Invention 4d 2.43 6.29 10.44 13.11 18.42 40% 20.5

Tables 2A and 2B combined show separates mechanical characteristics intothree distinct groups. The invention samples are integrated. The BunchCompression data is important to the consumer because a product that istoo stiff when dry will be uncomfortable to wear as it will tend tochafe the inner thigh during movement. Further, a product that tends todisintegrate after becoming wet or soiled will also be uncomfortable towear as it will tend to remain bunched and not provide good coverage ofthe panty. Therefore, an optimized product should have a 1^(st) cycleDry Peak Force compression of between about 30 and 100 gf and a WetRecovery energy of between about 1 and 2 N*mm.

Kawabata drape testing is a common industrial standard method formeasuring the ability of a material to bend. Given the complex geometryof the intimate area, it has been found that a desirable dry bendingmeasurement according to this method is between 2 and 10.5 (gf*cm²)/cmas measured in either the MD or CD direction. A desirable wet bendingmeasurement is between 1.25 and 10 (gf*cm²)/cm as measured in either theMD or CD direction when 0.5 mls of 0.9% saline solution is slowly addedto the sample over a 5 minute period and the product tested on theKawabata instrument after a further 2 minute waiting period. Referringto the previous discussion about the desire for the product to notdisintegrate when wet, it is desirable that the wet bending measurementaccording to the Kawabata drape testing when ran for a wet sample shoulddrop less than about 50% of the measurement for the same sample whendry, such as, for example, less than about 40%, less than 30%, less than20%, or less than about 10%.

Without being bound by theory, it is understood that compressionrecovery is also important to consumers. Consumers want the product toremain in contact with their intimate area without exerting a noticeableor unpleasant pressure against the skin. It has been found that there isan optimum compressive energy of between about 10 and 20 N*mm. It isalso desirable to have a resiliency of between 20 and 50%. Further, itis desirable to have a compression profile that has a force of (N*mm) atdifferent percentages of compression that falls within the followingranges:

% Compression of product thickness N/mm optimal range  1-13 2.5 to 613-25 7 to 14 25-38 10 to 26 38-50 17 to 45

It has been surprisingly found that by having a percent compression ofproduct thickness exhibiting the N/mm optimal ranges from above, one cancreate a product that has a smooth compression profile during dynamicbodily movements.

The surprising value of these measurements is in identifying unique newstructures and products which have an optimized bunch compression inboth the dry and wet states over multiple cycles of movement, an abilityto conform to tight bending radii without creasing or breaking, and toprovide a moderate level of resiliency so as to be invisible to theconsumer while she is wearing the product.

In one embodiment, an absorbent article has a dry bending measurementaccording to the Kawabata method of between 2 and 10.5 (gf*cm²)/cm asmeasured in either the MD or CD direction or a wet bending measurementbetween 1.25 and 10 (gf*cm²)/cm as measured in either the MD or CDdirection, and in addition, optionally, one or more of any of thefollowing; a 1^(st) cycle Dry Peak Force compression of between about 30and 150 gf, a Wet Recovery energy of between about 1 and 2 N/mm, acompressive energy of between about 10 and 20 N/mm, a resiliency ofbetween 20 and 50%, or a speed of recovery as measured by theZ-Compressive slope (N/mm) at 1-13% of between 2 and 6 N/mm, at 13-25%of between 7 and 14 N/mm, at 25-38% of between 10 and 26 N/mm, or at38-50% of between 17 and 45 N/mm.

In one embodiment, an absorbent article has a speed of recovery asmeasured by the Z-Compressive slope (N/mm) at 1-13% of between 2 and 6N/mm, at 13-25% of between 7 and 14 N/mm, at 25-38% of between 10 and 26N/mm, or at 38-50% of between 17 and 45 N/mm, and in addition,optionally, one or more of any of the following; a 1^(st) cycle Dry PeakForce compression of between about 30 and 150 gf, a Wet Recovery energyof between about 1 and 2 N/mm, a compressive energy of between about 10and 20 N/mm, a resiliency of between 20 and 50%, or a dry bendingmeasurement according to the Kawabata method of between 2 and 10.5(gf*cm²)/cm as measured in either the MD or CD direction or a wetbending measurement between 1.25 and 10 (gf*cm²)/cm as measured ineither the MD or CD direction.

TABLE 3 Examples from combining different materials, cores, topsheetintegration, types of integration and resulting fluid handlingcharacteristics. FLUID Handling Testing NMR-K- NMR-K- NMR-K- ProfileProfile Profile Absorbent Blot, Total NMR- (% decay (% decay (% decayMaterial/ Topsheet Residual, Residual @60 @100 @300 System Integration?mg ml/mm sec) sec) sec) LiTS (g) Prior Art 1 None 80 1.25 0 8 12 0.32Prior Art 2 None 22 0.3 30 69 90 0.05 Invention 3a None 52 0.57 2 13 600.22 Invention 3b RIPS-DB1 21 0.33 85 87 89 0.05 Invention 3c Jellyfish18 0.29 87 90 93 0.04 Invention 3d Diamond 16 0.25 90 94 95 0.04Invention 4a None 52 0.57 2 13 60 0.22 Invention 4b RIPS-DB1 21 0.33 8587 89 0.05 Invention 4c Jellyfish 18 0.29 87 90 93 0.04 Invention 4dDiamond 16 0.25 90 94 95 0.04

Table 3 indicates the ability of the new absorbent structure to quicklydry the topsheet relative to current commercial products as measured bythe Mouse NMR K-Profile at 60 seconds, 100 seconds, or 300 seconds. TheMouse NMR method for residual fluid measures the ability of the newabsorbent structure to efficiently wick fluid away from the topsheetwithin the top millimeter of the topsheet. The LiTS method measuresresidual fluid within the topsheet. The Blot test assesses thecompetition for fluid between a skin analog and the absorbent product.

In one embodiment, as measured by the Mouse NMR K-Profile method, thenew absorbent article is able to remove more than 90% of the fluidwithin 300 seconds after insult, more than 70% of the fluid within 100seconds after insult, and more than 30% of the fluid within 60 secondsafter insult, and in addition, optionally, one or more of any of thefollowing; the ability to reduce the level of fluid remaining on theskin analog to a level below 20mg as measured by the Blot test, theability to reduce the residual fluid in the top 1 mm of the absorbentarticle to below 0.30 ml/mm as measured by the Mouse NMR method forresidual fluid, or the ability to reduce the residual fluid in atopsheet to a value of 0.04 g or less using the LiTS method formeasuring residual fluid.

In one embodiment, the new absorbent structure is able to reduce thelevel of fluid remaining on the skin analog to a level below 20 mg asmeasured by the Blot test, and in addition, optionally, one or more ofany of the following; the ability to remove more than 90% of the fluidwithin 300 seconds after insult, more than 70% of the fluid within 100seconds after insult, and more than 30% of the fluid within 60 secondsafter insult as measured by the Mouse NMR K-Profile method or theability to reduce the residual fluid in the top 1 mm of the absorbentarticle to below 0.30 ml/mm as measured by the Mouse NMR method forresidual fluid.

In one embodiment, the new absorbent structure is able to reduce theresidual fluid in the top 1 mm of the absorbent article to below 0.30ml/mm as measured by the Mouse NMR method for residual fluid, and inaddition, optionally, one or more of any of the following; the abilityto remove more than 90% of the fluid within 300 seconds after insult,more than 70% of the fluid within 100 seconds after insult, and morethan 30% of the fluid within 60 seconds after insult as measured by theMouse NMR K-Profile method or the ability to reduce the level of fluidremaining on the skin analog to a level below 20 mg as measured by theBlot test.

In one embodiment, the new absorbent structure is able to reduce theresidual fluid in a topsheet to a value of 0.04 g or less using the LiTSmethod for measuring residual fluid.

Improving mechanical properties of the absorbent product, such as itsability to conform to complex geometries via improved bendingproperties, optimized bunch compression and resiliency properties, andZ-compression has the potential to negatively affect fluid handlingproperties. For instance, as the absorbent article conforms to the bodybetter, the body exudates no longer contact the absorbent article over abroad area. Rather, the body exudates are more likely to contact thetopsheet of the absorbent article on a smaller portion of the topsheet.This results in a need for the absorbent article to also have animproved ability to transport larger amounts of fluid down and away fromthe point of fluid contact with the absorbent article. Not addressingthis need will leave the consumer feeling wet longer and dissatisfiedwith the product performance even though the product fits better and ismore comfortable to wear. Therefore, there is a need to provide anabsorbent article with improved fluid handling properties in combinationwith improvement of mechanical properties. The improved absorbentarticle disclosed herein addresses both of those needs via the followingcombinations.

In one embodiment, the new absorbent article has a dry bendingmeasurement between 2 and 10.5 gf*cm²/cm or a wet bending measurementbetween 1.25 and 10 gf*cm2/cm according to the Kawabata method measuredin either the MD or CD direction, and is able to remove more than 90% ofthe fluid within 300 seconds after insult, more than 60% of the fluidwithin 100 seconds after insult, or more than 30% of the fluid within 60seconds after insult according to the NMR K-Profile test method.

In one embodiment, the new absorbent article has a dry bendingmeasurement between 2 and 10.5 gf*cm²/cm or a wet bending measurementbetween 1.25 and 10 gf*cm2/cm according to the Kawabata method measuredin either the MC or CD direction, and is able to reduce the fluidremaining on the skin analog to below 20 mg, below 40 mg, or below 60 mgas measured by the Blot test.

In one embodiment, the new absorbent article is able to remove more than90% of the fluid within 300 seconds after insult, more than 60% of thefluid within 100 seconds after insult, or more than 30% of the fluidwithin 60 seconds after insult and has a bunch compression ratio of1^(st) cycle dry peak force (gf) over 5^(th) cycle wet recovery energy(N*mm) of between 45 and 135 gf/N*mm.

In one embodiment, the new absorbent article has a bunch compressionratio of 1^(st) cycle dry peak force (gf) over 5^(th) cycle wet recoveryenergy (N*mm) of between 45 and 135 gf/N*mm and is able to reduce thefluid remaining on the skin analog to below 20 mg, below 40 mg, or below60 mg as measured by the Blot test.

Further, by utilizing repeating patterns of bending models on ameso-scale versus historical macro scale that are bendable and shapeablebased on each user's unique anatomical shape and how the user deformsthe absorbent system while wearing, it has been found that one cancreate an absorbent structure that is able to have improved contactbetween the absorbent product and the user.

As used herein, meso-scale relates to a mechanical transformation thatdisplaces larger more infrequent modifications to the absorbent article.For instance, traditional absorbent articles may have two to seven zonesinvolving structures or mechanical transformations. In this context,meso-scale refers to a mechanical transformation that involves 10-70mechanical transformations within the absorbent article. For instance,traditional hot pin aperturing or needle punching involves 1 to 10fibers whereas a meso-scale mechanical transformation may involvegreater than 10 and up to 100 fibers or more. In another example, anabsorbent article may have one to five bending moments across the widthor length of the absorbent article. In contrast, a meso-scale mechanicaltransformation may involve 5 to 50 transformations.

Without being bound by theory, applicants have found that it isdesireable to create a repeating pattern of bending modes delivered byformation means that is significantly more that has ever been offeredbefore and to do this without compromising resiliency or impartingdiscomfort. This improved bending is exemplified using the BC, Kawabatatest method plus the z-compression method. The Increased dynamic bodyconformance promotes a panty-like fit experience. Further, without beingbound by theory, it is believed that the proposed method and combinationof selective materials may lead to the creation of pillow-like 3Dtopography creates structures that have a low initial stiffness gradientin the first 50% of compression as this compression increases thestiffness gradient becomes stiffer becoming equivalent or slightlygreater than the base structure due to the pre-compression built in tothe structure by topsheet integration. The low initial stiffnessgradient promotes the feeling of an airy soft feeling signaling comfortto her.

Textured surface and increased stiffness gradient (when compressed)aides in active cleaning of her body with an additional frictionalcomponent known as “plowing friction”. Locally skin/fat deforms downinto the undulations of the pad surface as her body and pad form aninterface and pressure is created. Pad and body move relative to oneanother fluid is wiped away by the pad and quickly wicked away from herbody by the highly absorbent TS/core assembly. Active or dynamiccleaning of her body gives her a clean, dry and fresh feeling.

The absorbent core structure may be attached to the topsheet, thebacksheet, or both the topsheet and backsheet using bonds, a bondinglayer, adhesives, or combinations thereof.

Adhesives may be placed in any suitable pattern, such as, for example,lines, spirals, points, circles, squares, or any other suitable pattern.Bonds may be placed in any suitable pattern, such as, for example,lines, spirals, points, circles, squares, or any other suitable pattern.

The absorbent layers may be combined using an intermediate layer betweenthe two layers. The intermediate layer may comprise a tissue, anonwoven, a film, or combinations thereof. The intermediate layer mayhave a permeability greater than the 200 Darcy.

FIG. 12 a perspective view of one embodiment of a sanitary napkin. Theillustrated sanitary napkin 10 has a body-facing upper side 11 thatcontacts the user's body during use. The opposite, garment-facing lowerside 13 contacts the user's clothing during use.

A sanitary napkin 10 can have any shape known in the art for femininehygiene articles, including the generally symmetric “hourglass” shape asshown in FIG. 12, as well as pear shapes, bicycle-seat shapes,trapezoidal shapes, wedge shapes or other shapes that have one end widerthan the other. Sanitary napkins and pantyliners can also be providedwith lateral extensions known in the art as “flaps” or “wings”. Suchextensions can serve a number of purposes, including, but not limitedto, protecting the wearer's panties from soiling and keeping thesanitary napkin secured in place.

The upper side of a sanitary napkin generally has a liquid pervioustopsheet 14. The lower side generally has a liquid impervious backsheet16 that is joined with the topsheet 14 at the edges of the product. Anabsorbent core 18 is positioned between the topsheet 14 and thebacksheet 16. A secondary topsheet may be provided at the top of theabsorbent core 18, beneath the topsheet.

The topsheet 12, the backsheet 16, and the absorbent core 18 can beassembled in a variety of well- known configurations, including socalled “tube” products or side flap products, such as, for example,configurations are described generally in U.S. Pat. No. 4,950,264,“Thin, Flexible Sanitary Napkin” issued to Osborn on Aug. 21, 1990, U.S.Pat. No. 4,425,130, “Compound Sanitary Napkin” issued to DesMarais onJan. 10, 1984; U.S. Pat. No. 4,321,924, “Bordered Disposable AbsorbentArticle” issued to Ahr on Mar. 30, 1982; U.S. Pat. No. 4,589,876, and“Shaped Sanitary Napkin With Flaps” issued to Van Tilburg on Aug. 18,1987. Each of these patents is incorporated herein by reference.

The backsheet 16 and the topsheet 14 can be secured together in avariety of ways. Adhesives manufactured by H. B. Fuller Company of St.Paul, Minn. under the designation HL-1258 or H-2031 have been found tobe satisfactory. Alternatively, the topsheet 14 and the backsheet 16 canbe joined to each other by heat bonding, pressure bonding, ultrasonicbonding, dynamic mechanical bonding, or a crimp seal. A fluidimpermeable crimp seal 24 can resist lateral migration (“wicking”) offluid through the edges of the product, inhibiting side soiling of thewearer's undergarments.

As is typical for sanitary napkins and the like, the sanitary napkin 10of the present invention can have panty-fastening adhesive disposed onthe garment-facing side of backsheet 16. The panty-fastening adhesivecan be any of known adhesives used in the art for this purpose, and canbe covered prior to use by a release paper, as is well known in the art.If flaps or wings are present, panty fastening adhesive can be appliedto the garment facing side so as to contact and adhere to the undersideof the wearer's panties.

The backsheet may be used to prevent the fluids absorbed and containedin the absorbent structure from wetting materials that contact theabsorbent article such as underpants, pants, pyjamas, undergarments, andshirts or jackets, thereby acting as a barrier to fluid transport. Thebacksheet according to an embodiment of the present invention can alsoallow the transfer of at least water vapour, or both water vapour andair through it.

Especially when the absorbent article finds utility as a sanitary napkinor panty liner, the absorbent article can be also provided with a pantyfastening means, which provides means to attach the article to anundergarment, for example a panty fastening adhesive on the garmentfacing surface of the backsheet. Wings or side flaps meant to foldaround the crotch edge of an undergarment can be also provided on theside edges of the napkin.

FIG. 13 is a cross-sectional view of the sanitary napkin 10 of FIG. 12,taken through line 2-2. As shown in the figure, the absorbent core 18structure comprises of a heterogeneous mass 22 comprising open-cell foampieces 25. The topsheet is integrated into the heterogeneous mass 22forming wells 32.

FIG. 14 is a zoomed in version of a portion of FIG. 13. As shown in FIG.14, The topsheet 12 is incorporated into the absorbent core 18comprising a heterogeneous mass 22 stratum. The heterogeneous mass 22has open cell foam pieces 25. A well is 32 is shown between the opencell foam pieces 25. A group of fibers 74 is in the same X-Y plane asthe heterogeneous mass 22 layer from the topsheet 12.

FIG. 15 is an SEM micrograph of a heterogeneous mass 22 prior to anyformation means or forming of canals. As shown in FIG. 15, the absorbentstratum 40 is a heterogeneous mass 22 comprising a first planar nonwoven44 having a first surface 46 and a second surface 48 and a second planarnonwoven 50 having a first surface 52 and a second surface 54. An opencell foam piece 25 enrobes a portion of the first planar nonwoven 44 anda portion of the second planar nonwoven 50. Specifically, the open cellfoam piece 25 enrobes enrobeable elements 58 in both the second surface48 of the first planar nonwoven 44 and the first surface 52 of thesecond planar nonwoven 50.

FIG. 16 is an SEM micrograph of a heterogeneous mass 22 after formationmeans. As shown in FIG. 16, the absorbent stratum 40 is a heterogeneousmass 22 comprising a first planar nonwoven 44 having a first surface 46and a second surface 48 and a second planar nonwoven 50 having a firstsurface 52 and a second surface 54. An open cell foam piece 25 enrobes aportion of the first planar nonwoven 44 and a portion of the secondplanar nonwoven 50. The planar nowovens are shown as wavy due to theimpact of the formation means.

FIGS. 17 and 18 are top views of a topsheet 12 that has been integratedwith a heterogeneous mass 22 stratum. A top view of one or more wells 32or points of topsheet discontinuity 76 are indicated. FIG. 17 has beencreated using polarized light.

FIG. 19 is a cross section view of a portion of FIG. 18. FIG. 19 is anSEM micrograph of a heterogeneous mass 22 after formation means. Asshown in FIG. 19, the absorbent stratum 40 is a heterogeneous mass 22comprising a first planar nonwoven 44 having a first surface 46 and asecond surface 48 and a second planar nonwoven 50. An open cell foampiece 25 enrobes a portion of the first planar nonwoven 44 and a portionof the second planar nonwoven 50. The planar nowovens are shown as wavydue to the impact of the formation means. Wells 32 or points of topsheetdiscontinuity 76 are shown between the open cell foam pieces 25. A groupof fibers 74 is in the same X-Y plane as the heterogeneous mass 22layer. The distal end of a well is shown as 78. As shown in FIG. 19, byintegrating the topsheet with the absorbent structure, one reduces thedistance in an X-Y plane (X-Y distance) 82 that fluid must travel to beabsorbed into the absorbent core structure. As fluid goes deeper intothe well 32, the X-Y distance 82 becomes small within each X-Y planecreating a higher capillary cascade. This is shown by the two X-Ydistance arrows identified as 82. This is unlike the traditional fluidpath wherein fluid travels a vertical distance or Z-distance 87 througha non-integrated portion of the topsheet before reaching the core.

FIGS. 20 and 21 are top views of a topsheet 12 that has been integratedwith a heterogeneous mass 22. A top view of one or more wells 32 orpoints of topsheet discontinuity 76 are indicated. FIG. 20 has beencreated using polarized light.

FIG. 22 is a cross section view of a portion of FIG. 21. FIG. 22 is anSEM micrograph of a heterogeneous mass 22 after formation means. Asshown in FIG. 22, the absorbent stratum 40 is a heterogeneous mass 22comprising a first planar nonwoven 44 and a second planar nonwoven 50.An open cell foam piece 25 enrobes a portion of the first planarnonwoven 44 and a portion of the second planar nonwoven 50. The planarnowovens are shown as wavy due to the impact of the formation means. Oneor more wells 32 or points of topsheet discontinuity 76 are shownbetween the open cell foam pieces 25. A group of fibers 74 is in thesame X-Y plane as the heterogeneous mass 22 layer. The distal end of awell is shown as 78.

FIG. 23 is a zoomed in portion of FIG. 22. FIG. 23 is an SEM micrographof a heterogeneous mass 22 after formation means. As shown in FIG. 23,the absorbent stratum 40 is a heterogeneous mass 22 comprising a firstplanar nonwoven 44 and a second planar nonwoven 50. An open cell foampiece 25 enrobes a portion of the first planar nonwoven 44 and a portionof the second planar nonwoven 50. The planar nowovens are shown as wavydue to the impact of the formation means. A well 32 or point of topsheetdiscontinuity 76 is shown between the open cell foam pieces 25. A groupof fibers 74 is in the same X-Y plane as the heterogeneous mass 22layer. The distal end of a well is shown as 78.

FIGS. 24 is a top views of a topsheet 12 that has been integrated with aheterogeneous mass 22 stratum. One or more wells are indicated as 32.

FIG. 25 is a cross section view of a portion of FIG. 24. FIG. 25 is anSEM micrograph of a heterogeneous mass 22 after formation means. Asshown in FIG. 22, the absorbent stratum 40 is a heterogeneous mass 22comprising a first planar nonwoven 44 and a second planar nonwoven 50.An open cell foam piece 25 enrobes a portion of the first planarnonwoven 44 and a portion of the second planar nonwoven 50. The planarnowovens are shown as wavy due to the impact of the formation means. Awell 32 or point of topsheet discontinuity 76 is shown between the opencell foam pieces 25. A group of fibers 74 is in the same X-Y plane asthe heterogeneous mass 22 layer. The distal end of a well is shown as78.

FIG. 26 is a zoomed in view of a portion of FIG. 25. FIG. 26 is an SEMmicrograph of a heterogeneous mass 22 after formation means. As shown inFIG. 26, the absorbent stratum 40 is a heterogeneous mass 22 comprisinga first planar nonwoven 44 having a first surface 46 and a secondsurface 48 and a second planar nonwoven 50. An open cell foam piece 25enrobes a portion of the first planar nonwoven 44 and a portion of thesecond planar nonwoven 50. The planar nowovens are shown as wavy due tothe impact of the formation means. A well 32 or point of topsheetdiscontinuity 76 is shown between the open cell foam pieces 25. A groupof fibers 74 is in the same X-Y plane as the heterogeneous mass 22layer. The distal end of a well is shown as 78.

FIGS. 27-29 are images of different topsheets 12 that have beenintegrated with a heterogeneous mass 22 stratum. FIGS. 27-29 showelongated wells 32 and non-deformed areas 33 that have not been treatedwith a deformation means. FIG. 29 show a first zone 80 and a second zone81 and a first boundary 84 and a second boundary 85. FIG. 29 is aconceptual core showing a plurality of zones within the same product.The different zones are created using forming means. In this case, thecore may be modified to provide optimum fluid acquisition in the middle,optimum fluid transportation in the front and back, and enhanced barrier(height, absorbency, etc.) around the perimeter of the pad. The core ofFIG. 29 is not to be considered a limiting embodiment. One of ordinaryskill in the art would, upon seeing the core of FIG. 29, understand thatthe core may comprise additional zones such as, for example, between 2and 10 zones, such as, for example, 3 zones, 4 zones, 5 zones, 6 zones,7 zones, 8 zones, or 9 zones.

Additionally, each one exhibits a distinct topographical surface andvisual geometry. As shown in FIG. 29, more than one geometry may belocated within a single absorbent article.

ZD Compression

The ZD compression of a specimen is measured on a constant rate ofextension tensile tester (a suitable instrument is the MTS Allianceusing Testworks 4.0 Software, as available from MTS Systems Corp., EdenPrairie, Minn.) using a load cell for which the forces measured arewithin 10% to 90% of the limit of the cell. The bottom stationaryfixture is a circular, stainless steel platen 100 mm in diameter, andthe upper movable fixture is a circular, stainless steel platen 40.00 mmin diameter. Both platens have adapters compatible with the mounts ofthe tensile tester, capable of securing the platens parallel to eachother and orthogonal to the pull direction of the tensile tester. Alltesting is performed in a room controlled at 23° C. ±3C° and 50%±2%relative humidity.

Samples are conditioned at 23° C.±3C° and 50%±2% relative humidity twohours prior to testing. Identify the longitudinal and lateral center ofthe product. Remove the layer of interest from the article usingcryo-spray as needed. From the longitudinal and lateral midpoint, diecut a square 50.0±0.05 mm. Specimens are prepared from five replicatesamples.

Before the compression test can be performed, the caliper of a specimenis measured using a calibrated digital linear caliper (e.g., Ono SokkiGS-503 or equivalent) fitted with a 24.2 mm diameter foot with an anvilthat is large enough that the specimen can lie flat. The foot applies aconfining pressure of 0.69 kPa to the specimen. Zero the caliper footagainst the anvil. Lift the foot and insert the specimen flat againstthe anvil with its longitudinal and lateral midpoint centered under thefoot. Lower the foot at about 5 mm/sec onto the specimen. Read thecaliper (mm) 5.0 sec after resting the foot on the specimen and recordto the nearest 0.01 mm.

Set the nominal gage length between the platens to approximately 3 mmgreater than the specimens to be tested. Place the specimen, body facingside upward, onto the bottom platen with the longitudinal and lateralmidpoint of the specimen centered under the upper platen. Zero thecrosshead and load cell. Lower the crosshead at 1.00 mm/s until thedistance between the bottom surface of the upper platen and the uppersurface of the bottom platen is equal to the measured caliper of thespecimen. This is the adjusted gage length. Start data collection at arate of 100 Hz. Lower the crosshead at 1.00 mm/s to 50% of the adjustedgage length. Hold for 0.00 sec and then return the crosshead to theadjusted gage length. Immediately repeat this cycle for four additionalcycles. Return the crosshead to the nominal gage length and remove thespecimen. From the resulting Force (N) versus Displacement (mm) curves,calculate and record the Peak Force (N) for Cycle 1 and Cycle 5 to thenearest 0.01N.

In like fashion, repeat the measure for a total of 5 replicate samples.Calculate and report the arithmetic mean for the five Peak Force (N) forCycle 1 and Peak Force (N) for Cycle 5 values separately to the nearest0.01N.

Bunch Compression Test

Bunched Compression of a sample is measured on a constant rate ofextension tensile tester (a suitable instrument is the MTS Allianceusing Testworks 4.0 software, as available from MTS Systems Corp., EdenPrairie, MN, or equivalent) using a load cell for which the forcesmeasured are within 10% to 90% of the limit of the cell. All testing isperformed in a room controlled at 23° C.±3C° and 50%±2% relativehumidity. The test can be performed wet or dry.

As shown in FIG. 30, The bottom stationary fixture 3000 consists of twomatching sample clamps 3001 each 100 mm wide each mounted on its ownmovable platform 3002 a, 3002 b. The clamp has a “knife edge” 3009 thatis 110 mm long, which clamps against a 1 mm thick hard rubber face 3008.When closed, the clamps are flush with the interior side of itsrespective platform. The clamps are aligned such that they hold anun-bunched specimen horizontal and orthogonal to the pull axis of thetensile tester. The platforms are mounted on a rail 3003 which allowsthem to be moved horizontally left to right and locked into position.The rail has an adapter 3004 compatible with the mount of the tensiletester capable of securing the platform horizontally and orthogonal tothe pull axis of the tensile tester. The upper fixture 2000 is acylindrical plunger 2001 having an overall length of 70 mm with adiameter of 25.0 mm. The contact surface 2002 is flat with no curvature.The plunger 2001 has an adapter 2003 compatible with the mount on theload cell capable of securing the plunger orthogonal to the pull axis ofthe tensile tester.

Samples are conditioned at 23° C.±3C° and 50%±2% relative humidity forat least 2 hours before testing. When testing a whole article, removethe release paper from any panty fastening adhesive on the garmentfacing side of the article. Lightly apply talc powder to the adhesive tomitigate any tackiness. If there are cuffs, excise them with scissors,taking care not to disturb the top sheet of the product. Place thearticle, body facing surface up, on a bench. On the article identify theintersection of the longitudinal midline and the lateral midline. Usinga rectangular cutting die, cut a specimen 100 mm in the longitudinaldirection by 80 mm in the lateral direction, centered at theintersection of the midlines. When testing just the absorbent body of anarticle, place the absorbent body on a bench and orient as it will beintegrated into an article, i.e., identify the body facing surface andthe lateral and longitudinal axis. Using a rectangular cutting die, cuta specimen 100 mm in the longitudinal direction by 80 mm in the lateraldirection, centered at the intersection of the midlines.

The specimen can be analyzed both wet and dry. The dry specimen requiresno further preparation. The wet specimens are dosed with 7.00 mL±0.01 mL10% w/v saline solution (100.0 g of NaCl diluted to 1 L deionizedwater). The dose is added using a calibrated Eppendorf-type pipettor,spreading the fluid over the complete body facing surface of thespecimen within a period of approximately 3 sec. The wet specimen istested 15.0 min±0.1 min after the dose is applied.

Program the tensile tester to zero the load cell, then lower the upperfixture at 2.00 mm/sec until the contact surface of the plunger touchesthe specimen and 0.02 N is read at the load cell. Zero the crosshead.Program the system to lower the crosshead 15.00 mm at 2.00 mm/sec thenimmediately raise the crosshead 15.00 mm at 2.00 mm/sec. This cycle isrepeated for a total of five cycles, with no delay between cycles. Datais collected at 100 Hz during all compression/decompression cycles.

Position the left platform 3002 a 2.5 mm from the side of the upperplunger (distance 3005). Lock the left platform into place. Thisplatform 3002 a will remain stationary throughout the experiment. Alignthe right platform 3002 b 50.0 mm from the stationary clamp (distance3006). Raise the upper probe 2001 such that it will not interfere withloading the specimen. Open both clamps. Referring to FIG. 31a , placethe specimen with its longitudinal edges (i.e., the 100 mm long edges)within the clamps. With the specimen laterally centered, securely fastenboth edges. Referring to FIG. 31b , move the right platform 3002 btoward the stationary platform 3002 a a distance 20.0 mm. Allow thespecimen to bow upward as the movable platform is positioned. Manuallylower the probe 2001 until the bottom surface is approximately 1 cmabove the top of the bowed specimen.

Start the test and collect displacement (mm) verses force (N) data forall five cycles. Construct a graph of Force (N) versus displacement (mm)separately for all cycles. A representative curve is shown in FIG. 32a .From the curve record the Maximum Compression Force for each Cycle tothe nearest 0.01N. Calculate the % Recovery between the First and Secondcycle as (TD-E2)/(TD-E1)*100 where TD is the total displacement and E2is the extension on the second compression curve that exceeds 0.02 N.Record to the nearest 0.01%. In like fashion calculate the % Recoverybetween the First Cycle and other cycles as (TD-E_(i))/(TD-E1)*100 andreport to the nearest 0.01%. Referring to FIG. 32b , calculate theEnergy of Compression for Cycle 1 as the area under the compressioncurve (i.e., area A+B) and record to the nearest 0.1 mJ. Calculate theEnergy Loss from Cycle 1 as the area between the compression anddecompression curves (i.e., Area A) and report to the nearest 0.1 mJ.Calculate the Energy of Recovery for Cycle 1 as the area under thedecompression curve (i.e. Area B) and report to the nearest 0.1 mJ. Inlike fashion calculate the Energy of Compression (mJ), Energy Loss (mJ)and Energy of Recovery (mJ) for each of the other cycles and record tothe nearest 0.1 mJ

For each sample, analyze a total of five (5) replicates and report thearithmetic mean for each parameter. All results are reportedspecifically as dry or wet including test fluid (0.9% or 10%).

Kawabata Bending Rigidity

Bending rigidity is measured using a Kawabata Evaluation SystemKES-FB2-A, Pure Bend Tester Sensor (available from Kato Tech Co., Japan)and is reported in gfcm²/cm for both machine direction(MD) and crossdirection (CD). The instrument is calibrated as per the manufacturer'sinstructions. All testing is performed at about 23 ° C.±2 C.° and about50%±2% relative humidity.

The Bending Rigidity is measured as the slope between 0.0 cm⁻¹ and 0.25cm⁻¹ and −0.0 cm⁻¹ and −0.25 cm⁻¹. Instrument conditions are set asMaximum curvature: Kmax=±2.5 cm⁻¹, Cycles=1, Bending rate=2.5 cm⁻¹/sec.The sensitivity is set appropriately for the sample's rigidity but anominal value of 50 is representative.

Articles or materials are preconditioned at about 23° C.±2 C.° and about50%±2% relative humidity for 2 hours prior to testing. If the sample isan article, remove the layer of interest from the article usingcryo-spray as needed. The “Standard Condition” specimen size is 20.0 cmx 20.0 cm, and should be used when available. If the standard size isnot available cut the width of the specimen to the nearest cm (e.g., ifthe width is 17.4 cm, cut to 17.0 cm) then use the “Optional Condition”setting on the instrument to specify the width to the nearest cm. Ifnecessary based on the rigidity of the specimen, the width can bereduced to allow measurement of the specimen within the instrumentscapability. A total of ten (10) specimens are prepared, five for testingin each MD and CD direction.

Insert the specimen into the instrument with the body facing surfacedirected upward, such that the bending deformation is applied to thewidth direction. Start the test and record Bending Rigidity to thenearest 0.01 gfcm²/cm. Repeat testing for all specimens. CalculateBending Rigidity as the geometric mean of the five CD specimens and ofthe five MD specimens and report separately to the nearest 0.01gfcm²/cm.

Capillary Work Potential

Pore Volume Distribution measures the estimated porosity of theeffective pores within an absorbent body. The approach (i) appliespre-selected, incremental, hydrostatic air pressure to a material thatmay absorb/desorb fluid through a fluid saturated membrane and (ii)determines the incremental and cumulative quantity of fluid that isabsorbed/desorbed by the material at each pressure. A weight ispositioned on the material to ensure good contact between the materialand membrane and to apply an appropriate mechanical confining pressure.Pore Volume Distribution for a sample may be measured between about 5 μmand 1000 μm. From the distribution curves the Capillary Work Potential(CWP) can be calculated.

A representative instrument is a one based on the TRI/Autoporosimeter(TRI/Princeton Inc. of Princeton, N.J.), in which the operation and datatreatments is described in The Journal of Colloid and Interface Science162(1994), pp. 163-170, incorporated here by reference.

A representation of the equipment is shown in FIG. 33 and consists of abalance 800 with fluid reservoir 801 which is in direct fluidcommunication with the sample 811 which resides in a sealed,air-pressurized sample chamber 810.

Determining the Pore Volume Uptake or Pore-Size Distribution involvesrecording the increment of liquid that enters or leaves a porousmaterial as the surrounding air pressure is altered. A sample in thetest chamber is exposed to precisely controlled changes in air pressure.As the air pressure increases or decreases, the void spaces or pores ofthe porous media de-water or uptake fluid, respectively. Total fluiduptake is determined as the total volume of fluid absorbed by the porousmedia.

Pore-Size Distribution can further be determined as the distribution ofthe volume of uptake of each pore-size group, as measured by theinstrument at the corresponding pressure. The pore size is taken as theeffective radius of a pore and is related to the pressure differentialby the following relationship:

Pressure differential=[2γ cos Θ]/effective radius where γ=liquid surfacetension, and Θ=contact angle

For this experiment: γ=27 dyne/cm² divided by the acceleration ofgravity; cos Θ=1° The automated equipment operates by precisely changingthe test chamber air pressure in user-specified increments, either bydecreasing pressure (increasing pore size) to cause fluid uptake by theporous media, or by increasing pressure (decreasing pore size) to drainthe porous media. The liquid volume absorbed (drained) at each pressureincrement yields the pore size distribution. The fluid uptake is thecumulative volume for all pores taken up by the porous media, as itprogresses to saturation (e.g. all pores filled).

Experimental Conditions

Take a 9 cm diameter, 0.22 μm membrane filter (mixed cellulose esters,Millipore GSWP, EMD Millipore Corp., Billerica Mass.) by adhering thefilter to a 9 cm diameter by 0.6 cm thick Monel porous frit 807(available from Mott Corp, CT) using KRYLON® spray paint (FilmToolsGloss White Spray Paint #1501). Allow the frit/membrane to dry beforeuse.

Fill the inner base 812 of the sample chamber with hexadecane (availablefrom Sigma-Aldrich CAS #544-76-3). Place the frit 807 membrane side uponto the base of the sample chamber 810, and secure it into place with alocking collar 809. Fill the connecting tube 816, reservoir 802, and thefrit 807 with hexadecane assuring that no bubbles are trapped within theconnecting tube or the pores within the frit and membrane. Using thelegs of the base 811, level the sample camber and align the membranewith the top surface of the fluid within the reservoir. Dye cut aspecimen 5.5 cm square. Measure the mass of the specimen to the nearest0.1 mg. A 5.5 cm square, Plexiglas cover plate 804 and confining weight803 are selected to provide a confining pressure of 0.25 psi.

Place the top of the sample chamber 808 in place and seal the chamber.Apply the appropriate air pressure to the cell (connection 814) toachieve a 5 μm effective pore radius. Close the liquid valve 815. Openthe sample chamber, place the specimen 805, cover plate 804 andconfining weight 803 into the chamber onto the membrane 806 and seal thecamber. Open the liquid valve 815 to allow free movement of liquid tothe balance.

Progress the system through a sequence of pore sizes (pressures) asfollows (effective pore radius in μm): 5, 10, 20, 30, 40, 50, 60, 70,80, 90,100, 120,140, 160,180, 200, 250, 300, 350,400, 450, 500, 500,550, 600, 700, 800, 1000, 800, 700, 600, 550, 500, 450, 400, 350, 300,250, 200, 180, 160, 140, 120, 100, 90, 80, 70, 60, 50, 40, 30, 20, 10,5, 10, 20, 30, 40, 50, 60, 70, 80, 90,100, 120,140, 160,180, 200, 250,300, 350,400, 450, 500, 500, 550, 600, 700, 800, 1000. The sequence isprogressed to the next radius when an equilibrium rate of less than 25mg/min is measured at the balance.

In like fashion, measure the acquisition/drainage/acquisition cycleblank without a sample. Based on the incremental volume values,calculate the blank-corrected values for cumulative volume.

Cumulative Volume (mm³/mg)=[Specimen Fluid Uptake (mg)−Blank FluidUptake (mg)]/Density of Hexadecane (g/cm³)/Sample Mass (mg)

The Capillary Work Potential (CWP) is the work done by the samplenormalized by the area of the specimen. The trapezoidal rule is used tointegrate the ith pressure as a function of cumulative volume over ndata points:

${{CWP}\left\lbrack \frac{mJ}{m^{2}} \right\rbrack} = {\frac{W}{A_{w}} = {\sum\limits_{i = 1}^{n}{\frac{1}{2}\frac{{m_{w}\left( {{CV_{i + 1}} - {CV_{i}}} \right)}\left( {P_{i} + P_{i + 1}} \right)}{A_{w}}\left( {1{0^{3}\left\lbrack \frac{mJ}{J} \right\rbrack}} \right)}}}$

where

m_(w)=mass of web (mg)

CV=Cumulative Volume (m³/mg)

P=Air Pressure (Pa)

A_(w)=Area (m²)

Record the CWP to the nearest 0.1 mJ/m². In like fashion, repeat themeasure on a total of three (3) replicate specimens. Calculate thearithmetic mean of the replicates and report to the nearest 0.1 mJ/m².

Kinetics and 1D Liquid Distribution by NMR-MOUSE

The NMR-MOUSE (Mobile Universal Surface Explorer) is a portable open NMRsensor equipped with a permanent magnet geometry that generates a highlyuniform gradient perpendicular to the scanner surface. A frame 1007 withhorizontal plane 1006 supports the specimen and remains stationaryduring the test. A flat sensitive volume of the specimen is excited anddetected by a surface rf coil 1012 placed on top of the magnet 1010 at aposition that defines the maximum penetration depth into the specimen.By repositioning the sensitive slice across the specimen by means of ahigh precision lift 1008, the scanner can produce one-dimensionalprofiles of the specimen's structure with high spatial resolution.

An exemplary instrument is the Profile NMR-MOUSE model PM25 withHigh-Precision Lift available from Magritek Inc., San Diego, Calif.Requirements for the NMR-MOUSE are a 100 μm resolution in thez-direction, a measuring frequency of 13.5 MHz, a maximum measuringdepth of 25 mm, a static gradient of 8 T/m, and a sensitive volume (x-ydimension) of 40 by 40 mm². Before the instrument can be used, performphasing adjustment, check resonance frequency and check external noiselevel as per the manufacturer's instruction. A syringe pump capable ofdelivering test fluid in the range of 1 mL/min to 5 mL/min±0.01 mL/minis used to dose the specimen. All measurements are conducted in a roomcontrolled at 23° C.±0.5° C. and 50%±2% relative humidity.

The test solution is Paper Industry Fluid (PIF) prepared as 15 gcarboxymethylcellulose, 10 g NaCl, 4 g NaHCO₃, 80 g glycerol (allavailable from SigmaAldrich) in 1000 g distilled water. 2 mM/L ofDiethylenetriaminepentaacetic acid gadolinium (III) dihydrogen salt(available from SigmaAldrich) is added to each. After addition thesolutions are stirred using an shaker at 160 rpm for one hour.Afterwards the solutions are checked to assure no visible undissolvedcrystals remain. The solution is prepared 10 hours prior to use.

Products for testing are conditioned at 23° C.±0.5° C. and 50%±2%relative humidity for two hours prior to testing. Identify theintersection of the lateral and longitudinal center line of the product.Cut a 40.0 mm by 40.0 mm specimen from the product, centered at thatintersection, with the cut edges parallel and perpendicular to thelongitudinal axis of the product. The garment facing side of thespecimen 1003 is mounted on a 50 mm×50 mm×0.30 mm glass slide 1001 usinga 40.0 mm by 40.0 mm piece of double-sided tape 1002 (tape must besuitable to provide NMR Amplitude signal). A top cap 1004 is prepared byadhering two 50 mm×50 mm×0.30 mm glass slides 1001 together using a 40mm by 40 mm piece of two-sided tape 1002. The cap is then placed on topof the specimen. The two tape layers are used as functional markers todefine the dimension of the specimen by the instrument.

First a 1-D Dry Distribution Profile of the specimen is collected. Placethe prepared specimen onto the instrument aligned over top the coils.Program the NMR-MOUSE for a Carr-Purcell-Meiboom-Gill (CPMG) pulsesequence consisting of a 90° x -pulse follow by a refocusing pulse of180 ° y -pulse using the following conditions:

Repetition Time=500 ms

Number of Scans=8

Number of Echoes=8

Resolution=100 μm

Step Size=−100 μm

Collect NMR Amplitude data (in arbitrary units, a.u.) versus depth (μm)as the high precision lift steps through the specimen's depth. Arepresentative graph is shown in FIG. 36a . The second measure is theKinetic Experiment of the test fluid moving though the sensitive NMRvolume as test fluid is slowly added to the top of the specimen. The“trickle” dose is followed by a “gush” dose added using a calibrateddispenser pipet. Program the NMR-MOUSE for a CPMG pulse sequence usingthe following conditions:

Measurement Depth=5 mm

Repetition Time=200 ms

90° Amplitude=−7 dB

180° Amplitude=0 dB

Pulse Length=5 μs Echo Time=90 μs

Number of Echoes=128

Echo Shift=1 μs

Experiments before trigger=50

Experiments after trigger=2000

Rx Gain=31 dB

Acquisition Time=8 μs

Number of Scans=1

Rx Phase is determined during the phase adjustment as described by thevendor. A value of 230° was typical for our experiments. Pulse lengthdepends on measurement depth which here is 5 mm. If necessary the depthcan be adjusted using the spacer 1011.

Using the precision lift adjust the height of the specimen so that thedesired target region is aligned with the instruments sensitive volume.Target regions can be chosen based on SEM cross sections. Program thesyringe pump to deliver 1.00 mL/min±0.01 mL for 1.00 min for PIF testfluid or 5.00 mL/min±0.01 mL for 1.00 min for 0.9% Saline test fluid.Start the measurement and collect NMR Amplitude (a.u.) for 50experiments before initiating fluid flow to provide a signal baseline.Position the outlet tube from the syringe pump over the center of thespecimen and move during applying liquid over the total sample surface,but do not touch the borders of the sample. Trigger the system tocontinue collection of NMR amplitude data while simultaneouslyinitiating fluid flow for 1 mL over 60 sec. At 300 sec after thetrigger, add 0.50 mL of test fluid at approximately 0.5 mL/sec to thecenter of the specimen via a calibrated Eppendorf pipet. Arepresentative example of the NMR Amplitude versus time graph is shownin FIG. 37.

The third measurement is a 1-D Wet Distribution Profile. Immediatelyafter the Kinetic measurement is complete, replace the cap on thespecimen. The Wet Distribution is run under the same experimentalconditions as the previous Dry Distribution, described above. Arepresentative graph is shown in FIG. 36 b.

Calibration of the NMR Amplitude for the Kinetic signal can be performedby filling glass vials (8 mm outer diameter and a defined inner diameterby at least 50 mm tall) with the appropriate fluid. Set the instrumentconditions as described for the kinetics experiment. A calibration curveis constructed by placing an increasing number of vials onto theinstrument (vials should be distributed equally over the 40 mm×40 mmmeasurement region) and perform the kinetic measurements. The volumesare calculated as the summed cross sectional area of the vials presentmultiplied by the z-resolution where Resolution (mm) is calculated as1/Acquisition Time (s) divided by the instruments Gradient Strength(Hz/mm). The Calibration of the NMR Amplitude for the DistributionProfile is performed as an internal calibration based on the dry and wetprofiles. In this procedure the area beneath wet and dry profile werecalculated and after subtracting them the total area (excluding markers)was obtained. This total area is correlated to the amount of appliedliquid (here 1.5 mL). The liquid amount (μL) per 100 μm step can then becalculated.

The dimensions and values disclosed herein are not to be understood asbeing strictly limited to the exact numerical values recited. Instead,unless otherwise specified, each such dimension is intended to mean boththe recited value and a functionally equivalent range surrounding thatvalue. For example, a dimension disclosed as “40 mm” is intended to mean“about 40 mm.”

Values disclosed herein as ends of ranges are not to be understood asbeing strictly limited to the exact numerical values recited. Instead,unless otherwise specified, each numerical range is intended to meanboth the recited values and any integers within the range. For example,a range disclosed as “1 to 10” is intended to mean “1, 2, 3, 4, 5, 6, 7,8, 9, and 10.”

All documents cited in the Detailed Description of the Invention are, inrelevant part, incorporated herein by reference; the citation of anydocument is not to be construed as an admission that it is prior artwith respect to the present invention. To the extent that any meaning ordefinition of a term in this document conflicts with any meaning ordefinition of the same term in a document incorporated by reference, themeaning or definition assigned to that term in this document shallgovern.

While particular embodiments of the present invention have beenillustrated and described, it would be obvious to those skilled in theart that various other changes and modifications can be made withoutdeparting from the spirit and scope of the invention. It is thereforeintended to cover in the appended claims all such changes andmodifications that are within the scope of this invention.

What is claimed is:
 1. A feminine hygiene pad comprising a topsheetcomprising a first fibrous nonwoven web, a backsheet, and an absorbentstructure comprising one or more layers including a heterogeneous masslayer comprising a combination of one or more discrete pieces of opencell foam and a second fibrous nonwoven web, wherein the one or morediscrete pieces of open cell foam enrobe fibers of the second fibrousnonwoven web; and wherein fibers of the first nonwoven web areincorporated into the heterogeneous mass such that fibers of the firstnonwoven web and the heterogeneous mass occupy the same X-Y plane,wherein the open cell foam comprises polyurethane foam or HIPE foam. 2.The absorbent article according to claim 1, wherein the absorbentstructure comprises a layer comprising absorbent polymer material. 3.The absorbent article according to claim 1, wherein the layer comprisingabsorbent polymer material has a basis weight of less than 250 g/m². 4.The absorbent article of claim 1, wherein one or more layers of theabsorbent structure are substantially free of cellulose fibers.
 5. Theabsorbent article of claim 1 wherein the fibers of the first nonwovenweb have been displaced in a Z direction into the heterogeneous mass toform a pattern of wells on the topsheet.
 6. The absorbent article ofclaim 1 wherein the discrete pieces of open cell foam comprisepolyurethane foam.
 7. The absorbent article of claim 1 wherein thediscrete pieces of open cell foam comprise HIPE foam.